# Are there any free / very cheap mods for improved MPG?



## XtremeRevolution (Jan 19, 2012)

93Cobra said:


> I searched through different threads but can't find anyone that has free or very cheap mods that increase gas mileage. I don't care about performance, just looking for improved gas mileage on an automatic LTZ. I would LOVE to increase my 34mpg up closer to 40mpg. This may be a tough thing to accomplish.
> Any thoughts or links for this newbie??


40mpg is probably not going to happen unless you drive 45-60mph and drive only highway. Most cruze Autos don't hit those numbers. 

You can however bypass the air intake resonator and its accompanied plumbing. 

Remove the airbox and you'll see a tube that runs down into the fenderwell with two plastic fasteners. Remove the fastener caps, then the fastener anchors, and pull up firmly on the tube and it will come out. There should be a gasket at the bottom of it. If not, its probably still on the resonator. Stick your hand down there and grab that as well and keep it with the tube you just removed. Put the intake back together and enjoy some free extra power and a slight fuel economy increase. Oh, and you'll be able to hear the turbo now too. 

I would also run at least midgrade fuel (89 octane). It has been tested and proven that these cars produce knock with 87 octane, and although the car will run just fine with it, it will run better and get better fuel economy with 89 octane. The improvement outweighs the extra cost of the higher octane fuel. I can't say I've noticed a difference going from 89 to 93 octane though.


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## boats4life (May 28, 2011)

Hypermiling is free, it just takes practice. Google is a great resource for some ways to do it.


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## Big Tom (Mar 8, 2011)

Put more air in your tires. I keep mine at 35 cold.


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## NickD (Dec 10, 2011)

We skipped a $10,000 rebate on a Silverado and a $7,000.00 rebate on an Impala for these reasons. But kind of took a raincheck on the Volt, would never get our extra $26,000.00 back and maybe a bit of headache with maintenance cost afterwards. 

We don't necessarily believe in rumors, but when they talk about 6-7 bucks a gallon for gas, tend to believe rumors like that. Suppose to have a known supply of natural gas for the next four thousand years, and add another 8,000 years of methane to that, depending on your source for this kind of information. Much cleaner burning fuels, but still stuck with an oil controlled congress. That is the major problem. Nothing is being done about nuclear fusion either. Enough deuterium in one gallon of seawater to power your vehicle for years. 

Instead we are going backwards by using corn and exporting our technology to China alone with our jobs.

Yes, tire pressure plays a role, always has, always checking my tires, but don't have to do that anymore, OnStar is as pressure monitoring systems are now mandatory on all vehicles. And that will only cost me a couple of hundred bucks extra per year. Will no longer pay four bucks for four brand new valve stems, if they leak or the battery goes bad, will cost more like a 160 bucks. But this is the governments way of making sure you keep your tires filled. The EPA with over 155 different blends of fuel doesn't help either.


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## XtremeRevolution (Jan 19, 2012)

Nick, if I remember correctly, GM stated that the Volt was not for buyers who were looking to save money, and in that regard I completely agree with them. 

The Cruze is an excellent car for that purpose.


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## 93Cobra (Feb 13, 2012)

XtremeRevolution said:


> You can however bypass the air intake resonator and its accompanied plumbing.
> 
> Remove the airbox and you'll see a tube that runs down into the fenderwell with two plastic fasteners. Remove the fastener caps, then the fastener anchors, and pull up firmly on the tube and it will come out. There should be a gasket at the bottom of it. If not, its probably still on the resonator. Stick your hand down there and grab that as well and keep it with the tube you just removed. Put the intake back together and enjoy some free extra power and a slight fuel economy increase. Oh, and you'll be able to hear the turbo now too.


I have been looking for a "how to" for this that also shows pictures. Does that exist anywhere here on the site? I like looking at the pictures before I jump in so that I can ask any obvious questions. 
Is this basically removing the air inlet tub from the bottom of the air box? If so, is the air the engine would be sucking in just going to be engine compartment air?


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## XtremeRevolution (Jan 19, 2012)

93Cobra said:


> I have been looking for a "how to" for this that also shows pictures. Does that exist anywhere here on the site? I like looking at the pictures before I jump in so that I can ask any obvious questions.
> Is this basically removing the air inlet tub from the bottom of the air box? If so, is the air the engine would be sucking in just going to be engine compartment air?


Correct, its the air inlet tube underneath the airbox. The air the engine will be sucking in may actually be colder than with the factory plumbing. 

Now, I'm not 100% sure how it is with other trims, but the Eco's front grille is not wide open. The factory plumbing for the intake pulls air from behind the little grill above the chevy bowtie. However, at least on the Cruze Eco, that grill is completely blocked off and doesn't have any holes, so the air is instead sucked in from the engine bay, which is hot air. If all Chevy Cruzes are like this, you are more likely to pull cooler air from the fenderwell by removing that inlet tube than you are with the stock intake system. 

I will try to get some pictures of this quick mod tomorrow and make a quick write-up.


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## cwerdna (Mar 10, 2011)

boats4life said:


> Hypermiling is free, it just takes practice. Google is a great resource for some ways to do it.


CleanMPG, - What is hypermiling An authoritative source on fuel economy and hypermiling
This Guy Can Get 59 MPG in a Plain Old Accord. Beat That, Punk. | Mother Jones

There are a few safe and legal practices such as smarter braking, face out parking and FASing while parking besides conserving momentum, anticipated lights and taking routes w/timed lights. The OP's goal really should be to reduce fuel usage, which isn't necessarily the same as trying to get the highest mpg figure.


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## 70x7 (Apr 24, 2011)

buy lighter shoes


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## sciphi (Aug 26, 2011)

Fill it with premium gas and don't go faster than the speed limit or 65 mph, whichever is slower. Of course, don't get run over by a stream of 18-wheelers for slightly better fuel economy.


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## NickD (Dec 10, 2011)

So why does a carburetor engine require a choke or a fuel injector engine require enrichment to start a cold vehicle. Its because a cold engine does not evaporate the fuel and a lot more of fuel is required to initially start it. The colder the weather, the more enrichment or choking is required.

Why is the thermostat in the Cruze set at 225*F instead of the long time standard of 195*F? To increase the vaporization of the fuel to increase the efficiency. Removing that air intake is exactly backwards, not only in theory, but in practice. Its true that colder air is far more dense, but then you also have an O2 sensor to compensate for that. Nitro works great for getting a very dense air into the combustion chamber, but a lot of fuel has to be added to it for proper combustion. A power increase, but certainly not a fuel economy. A nitro equipped vehicle hitting 200 mph, can empty a 27 gallon fuel tank in under ten minutes.

If you want better fuel economy, just leave that air intake like it is, was done that way intentionally to get a few mpg more. Nothing gives worse fuel economy than short trips with a cold engine.

To help with fuel evaporative problems, EPA has mandated oxygenated gasoline to help reduce CO emissions, but works 180* out of phase with fuel economy. Worse yet, paying four bucks a gallon for oxygen and not getting the same heat value out of that fuel. So fuel economy is far worse during the winter months. Living in northern Wisconsin, we were the last to get that, but started that about 15 years ago. All of my vehicles are getting far worse fuel economy in the winter months with this winter gas. Like 20% poorer on some vehicles. And the price of gas this time of the year set a new record for high prices. But trying to learn how to enjoy being screwed.


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## Patman (May 7, 2011)

NickD said:


> We skipped a $10,000 rebate on a Silverado and a $7,000.00 rebate on an Impala for these reasons. But kind of took a raincheck on the Volt, would never get our extra $26,000.00 back and maybe a bit of headache with maintenance cost afterwards.
> 
> We don't necessarily believe in rumors, but when they talk about 6-7 bucks a gallon for gas, tend to believe rumors like that. Suppose to have a known supply of natural gas for the next four thousand years, and add another 8,000 years of methane to that, depending on your source for this kind of information. Much cleaner burning fuels, but still stuck with an oil controlled congress. That is the major problem. Nothing is being done about nuclear fusion either. Enough deuterium in one gallon of seawater to power your vehicle for years.
> 
> ...


Amen to the taking a raincheck on the Volt $42000 with one option(the car) it is new technology and great if you don't have to go farther than 100 miles or get stuck in traffic which turns out to be downfall of the hybrid. Honestly, how long will the battery last and how much to replace. 

Checking the air pressure does not require On star. They will send you a note but just check it on you DIC. That will tell you the tire pressure. And if you look on your driver door jam it will tell you the recommended tire pressure is 35 PSI on all 4 tires and 60 on your spare. Sorry, I am one of the few that have one of those and used it already! LOL


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## sciphi (Aug 26, 2011)

NickD said:


> So why does a carburetor engine require a choke or a fuel injector engine require enrichment to start a cold vehicle. Its because a cold engine does not evaporate the fuel and a lot more of fuel is required to initially start it. The colder the weather, the more enrichment or choking is required.
> 
> Why is the thermostat in the Cruze set at 225*F instead of the long time standard of 195*F? To increase the vaporization of the fuel to increase the efficiency. Removing that air intake is exactly backwards, not only in theory, but in practice. Its true that colder air is far more dense, but then you also have an O2 sensor to compensate for that. Nitro works great for getting a very dense air into the combustion chamber, but a lot of fuel has to be added to it for proper combustion. A power increase, but certainly not a fuel economy. A nitro equipped vehicle hitting 200 mph, can empty a 27 gallon fuel tank in under ten minutes.
> 
> ...


The 1.4T is intercooled, which has far more effect on the air temperature than the outside air. I've seen 70*F engine air temperatures when the outside air has been well below freezing. The intercooler heat-soaked and heated up the air flowing across it. And, the OEM intake was designed with all its baffles/chambers to reduce noise and prevent little critters from nesting in the airbox, not get great MPG. Ridding the intake of those pre-airbox baffles leaves one with a freer flowing intake. Being a turbo engine, flow is a friend up to a point.


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## Big Tom (Mar 8, 2011)

Patman said:


> And if you look on your driver door jam it will tell you the recommended tire pressure is 35 PSI on all 4 tires and 60 on your spare. Sorry, I am one of the few that have one of those and used it already! LOL



Mine says 30 PSI


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## cruzin2012 (Jan 12, 2012)

sciphi said:


> The 1.4T is intercooled, which has far more effect on the air temperature than the outside air. I've seen 70*F engine air temperatures when the outside air has been well below freezing. The intercooler heat-soaked and heated up the air flowing across it. And, the OEM intake was designed with all its baffles/chambers to reduce noise and prevent little critters from nesting in the airbox, not get great MPG. Ridding the intake of those pre-airbox baffles leaves one with a freer flowing intake. Being a turbo engine, flow is a friend up to a point.


Have you removed yours for mileage?


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## SlvrECObullet (Feb 21, 2012)

Hypermiling.... free... and i'm learning... Gunna squeeze ever little oz of MPGs that I as a human can...


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## XtremeRevolution (Jan 19, 2012)

sciphi said:


> The 1.4T is intercooled, which has far more effect on the air temperature than the outside air. I've seen 70*F engine air temperatures when the outside air has been well below freezing. The intercooler heat-soaked and heated up the air flowing across it. And, the OEM intake was designed with all its baffles/chambers to reduce noise and prevent little critters from nesting in the airbox, not get great MPG. Ridding the intake of those pre-airbox baffles leaves one with a freer flowing intake. Being a turbo engine, flow is a friend up to a point.


I'm going to have to agree here. I have not noticed a fuel economy decrease in the current tank of gas after I bypassed that silly system. If anything, it went up. DIC is now showing 44.4MPG. 

The convoluted intake does nothing but quiet the turbo. I prefer to hear it. Along with engine RPM, it gives me another indicator of when to shift or to let off the gas a bit. If I hear the turbo, I'm pulling in more air and therefore burning more fuel.


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## XtremeRevolution (Jan 19, 2012)

SlvrECObullet said:


> Hypermiling.... free... and i'm learning... Gunna squeeze ever little oz of MPGs that I as a human can...


This! Within reason, of course, you can improve your fuel economy significantly. I have a writeup for this here for anyone who hasn't seen it yet:

http://www.cruzetalk.com/forum/27-fuel-economy/5387-how-get-better-fuel-economy.html


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## SlvrECObullet (Feb 21, 2012)

XtremeRevolution said:


> This! Within reason, of course, you can improve your fuel economy significantly. I have a writeup for this here for anyone who hasn't seen it yet:
> 
> http://www.cruzetalk.com/forum/27-fuel-economy/5387-how-get-better-fuel-economy.html


Yea I read.. that and alot of that is what I was doing anyways when I owned a manual not knowing what it was called... But now I "know" what it is and make more of an effort to stick to it. ITS Awesome!!!!


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## XtremeAaron (Jan 22, 2012)

XtremeRevolution said:


> Correct, its the air inlet tube underneath the airbox. The air the engine will be sucking in may actually be colder than with the factory plumbing.
> 
> Now, I'm not 100% sure how it is with other trims, but the Eco's front grille is not wide open. The factory plumbing for the intake pulls air from behind the little grill above the chevy bowtie. However, at least on the Cruze Eco, that grill is completely blocked off and doesn't have any holes, so the air is instead sucked in from the engine bay, which is hot air. If all Chevy Cruzes are like this, you are more likely to pull cooler air from the fenderwell by removing that inlet tube than you are with the stock intake system.
> 
> I will try to get some pictures of this quick mod tomorrow and make a quick write-up.


Interested in this write up. Will be looking for it!


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## 70AARCUDA (Nov 14, 2010)

...the *free*'est & *cheap*'est *FE* mod is to simply _"...lift your foot off the accelerator pedal...",_ ie: drive slightly _slower_, at 50-55 mph, instead of 60-65 mph_._


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## ErikBEggs (Aug 20, 2011)

At the risk of sounding like a jerk, I'm dead serious when I say don't drive. Seriously. 

Nothing will save more money. Carpool. Ride your bike to the plaza that is only a mile or 2 away. Combine your trips with the furthest destination first (more efficient this way). Also go to the do it yourself car wash instead of the automated drive through. Turn your car off whenever you can and get out of the car. 

Since I started using these little simple tips.. like riding my bike to the other side of my 2 mile long campus, my MPG has shot up simply because the trips I'm taking are necessary instead of convenient. It helps alot.


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## boats4life (May 28, 2011)

Erik's got a point, lol.


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## sciphi (Aug 26, 2011)

sciphi said:


> The 1.4T is intercooled, which has far more effect on the air temperature than the outside air. I've seen 70*F engine air temperatures when the outside air has been well below freezing. The intercooler heat-soaked and heated up the air flowing across it. And, the OEM intake was designed with all its baffles/chambers to reduce noise and prevent little critters from nesting in the airbox, not get great MPG. Ridding the intake of those pre-airbox baffles leaves one with a freer flowing intake. Being a turbo engine, flow is a friend up to a point.





cruzin2012 said:


> Have you removed yours for mileage?


That junk was ditched within the first few weeks of getting the car! I wanted to hear the turbo, and know when to get off the gas aurally. My ears are faster than the ScanGaugeII hooked up to the OBDII port, and my eyes can stay on the road instead of looking at the boost readout.


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## GoldenCruze (Dec 18, 2011)

I have to say something about tire pressures.

A couple of people are flatly stating that the pressure should be 35psi. My Cruze LT has 30psi on the door tag. So what I want to know is what the door tag says for other trim levels. And also what tire and wheel size is on the car. I know that a 17inch size is available in some cases, and there are also the LRR and 'standard' tires as well. So it very well could be that there are different pressures called for between them all.


It is important to follow Chevy's tire requirements. It has all been carefully thought out, engineered, and tested. Adding a significant amount of extra air to the tire can affect handling and shortening the life of the tire. You can be creating a safety hazard for yourself.


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## boats4life (May 28, 2011)

My eco states 35psi. It will depend on the wheel size and tire type, is my guess.


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## XtremeRevolution (Jan 19, 2012)

GoldenCruze said:


> I have to say something about tire pressures.
> 
> A couple of people are flatly stating that the pressure should be 35psi. My Cruze LT has 30psi on the door tag. So what I want to know is what the door tag says for other trim levels. And also what tire and wheel size is on the car. I know that a 17inch size is available in some cases, and there are also the LRR and 'standard' tires as well. So it very well could be that there are different pressures called for between them all.
> 
> ...


Respectfully, this is not true. It is not important to follow Chevy's tire requirements. Their requirements are an "optimal" pressure. 

If you reduce pressure, you gain traction and ride comfort, but sacrifice fuel economy. You also compromise tire wear and have more of a possibility of a blowout. Contrary to what may make sense in your mind, tires blow out due to insufficient pressure, not too much pressure. I've never seen a tire blow out because it was given too much pressure; its always the other way around. 

The only way you'd be creating a hazard is by reducing the traction ability of the car by increasing tire pressure. In fact, you gain tire life by increasing the pressure of the tires. You may be thinking of the pictures you've seen at your local tire store where the inner section of the tire is worn more than the outer section, and they use that as a recommendation to ensure that your tire pressure is accurate. This is not only false, but also misleading. So long as your tires are rotated at least every 10,000 miles, they will wear evenly regardless of tire pressure.

This was discussed endlessly on cleanmpg.com forums and the consensus was that increasing tire pressure to the maximum recommended on the sidewall will have the exact opposite with regard to tire wear as most people think. People who have used tire pressures above what the manufacturer recommends have gone 80-100k miles on tires rated for 40-50k. They end up having to replace them not due to wear, but dry rot.

Keep in mind that a tire with a higher pressure will have a lower rolling resistance. It will have less contact on the road per revolution, thus reducing its wear.



boats4life said:


> My eco states 35psi. It will depend on the wheel size and tire type, is my guess.


The truth is that tires will respond differently to different tire pressure. GM knows what they outfit from the factory, but they cannot make a valid recommendation for every tire you will install on the car after that. For example, 32/32 was the recommendation for the factory 215/65/15 tires on my 95 Regal when I bought it. I installed 235/60/15 tires shortly afterward and the front tires always looked flat. I needed to increase pressure on those to 44psi, the max on the sidewall, so that they would actually be reasonably inflated. I still got 45k miles out of them, which is exactly what they were rated for.


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## cwerdna (Mar 10, 2011)

Patman said:


> Amen to the taking a raincheck on the Volt $42000 with one option(the car) it is new technology and great if you don't have to go farther than 100 miles or get stuck in traffic which turns out to be downfall of the hybrid.


What does the 100 mile figure relate to? Elaborate on "get stuck in traffic which turns out to be downfall of the hybrid."


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## sedanman (Dec 10, 2010)

XtremeRevolution said:


> I'm going to have to agree here. *I have not noticed a fuel economy decrease in the current tank of gas after I bypassed that silly system.* If anything, it went up. DIC is now showing 44.4MPG.
> 
> The convoluted intake does nothing but quiet the turbo. I prefer to hear it. Along with engine RPM, it gives me another indicator of when to shift or to let off the gas a bit. *If I hear the turbo, I'm pulling in more air and therefore burning more fuel.*


hehehehehahahaha I love when people post contradictory statements. SO, you're burning more fuel and getting better fuel economy you say? hmmm? hehe

Getting back to the OP's question about how to cheaply get better fuel economy. Here's a suggestion: Keep the rpm low. That means shift sooner. And yes you can do this on the auto trans too. Of course this will slow down your acceleration but everything is a trade off.


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## boats4life (May 28, 2011)

sedanman said:


> hehehehehahahaha I love when people post contradictory statements. SO, you're burning more fuel and getting better fuel economy you say? hmmm? hehe
> 
> Getting back to the OP's question about how to cheaply get better fuel economy. Here's a suggestion: Keep the rpm low. That means shift sooner. And yes you can do this on the auto trans too. Of course this will slow down your acceleration but everything is a trade off.


Nothing he said in that post was contradictory, I think you misread.


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## NickD (Dec 10, 2011)

Twelve years ago, the DOT came into our city, did an evaluation, installed over 30 traffic lights, most with no right turn when red, dumped all the yield signs and replaced them with stop signs, and reduced practically all the speed limits. We have three major state highways running through town, rather than bypassing the city, tore down buildings and put major expressways down the middle. City hired a civil engineer to program all of the traffic lights, didn't know what he was doing, could spend ten minutes at a traffic light that was red to make a now forced left turn with not a soul in sight. Plus added hundreds of street lights, city is brighter at night than in the daytime. All at a time when energy costs are skyrocketing.

Year later, 9/11 came along, more than doubled the size of our police department with three new undercover cop cars. With nothing else to do except issued tickets. Got so bad, city had to elect a judge to hand the fines. Then came ethanol in gas. Takes an extra 15 minutes to cross town, engine spends more time idling than anything, solution, hybrid vehicles that really don't work in cold weather, and only work if you can coast a mile before stopping. Everyone is so impatient, can't do that.

Read they did the same thing in LA where they added 45 minutes to go anywhere. They also moved a historical train station that hasn't been used in over 44 years, is now a Japanese restaurant. The old Wisconsin Central RR was sold to the Canadians and instead of 20 freight cars, pulling trains 1.8 miles long. Nothing in town uses railways anymore, all 18 wheelers, did built a couple of overpasses on dead streets, main street in downtown is blocked for twenty minutes because the city imposed speed limits on these super long trains. Traffic blocks up for a mile.

Did build bike trails, they are nice, but don't go anywhere, but my dog and I like those, built a overpass over the new expressway and railroad track, think my dog and I are the only ones that use that, but when we cross over, have to do a U-turn because it doesn't go anywhere. Do have a major clinic and hospital in town where ten thousand people come in everyday, didn't do a thing with that, but built a school on one of the two lane access roads, loaded with cops, 10 mph speed zone, and kids constantly crossing during the rush hour.

Our county roads are the same, for every **** bar on these roads, not a soul in the daytime, cut the speed limit from 55 to 35 mph, not just for the bar, but 3/4 of a mile before and after. Yes you see cops hidden to enforce those speed limits.

So you want to save gas and get better fuel economy? Could try moving to a different country. USA is ran by idiots. Could try split fire spark plugs or hang a magnet on your fuel line. Or get a hybrid. Performance is also key, if you are trying to get on an expressway. With just about everyone, thousands of suburbs popped up jamming them with millions just going back and forth to return a DVD. Not good if you are traveling cross country. Sleeping during the day and driving at night does help a little, but not when driving through Chicago.


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## GoldenCruze (Dec 18, 2011)

What does that long rant have to with the cheap modifications?


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## 70AARCUDA (Nov 14, 2010)

GoldenCruze said:


> What does that long rant have to with the cheap modifications?


...*things* that help you save gas, because they make you _*slow down*_?


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## crzesk8dad (Jan 14, 2012)

:1poke:Lose 25 pounds. It's good enough for the spare tire, why not you?


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## Patman (May 7, 2011)

crzesk8dad said:


> :1poke:Lose 25 pounds. It's good enough for the spare tire, why not you?


Well I lost 12 lbs so far(in a contest) but still have a spare tire(in the trunk of the car) See if that improves my mileage.


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## 70AARCUDA (Nov 14, 2010)

....:th_salute: I salute you!


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## XtremeRevolution (Jan 19, 2012)

sedanman said:


> hehehehehahahaha I love when people post contradictory statements. SO, you're burning more fuel and getting better fuel economy you say? hmmm? hehe
> 
> Getting back to the OP's question about how to cheaply get better fuel economy. Here's a suggestion: Keep the rpm low. That means shift sooner. And yes you can do this on the auto trans too. Of course this will slow down your acceleration but everything is a trade off.


Please tone down the attitude. I think I speak for everyone here when I say that we have zero need for condescending attitudes and "better than thou" auras such as the one you just carried. If something doesn't make sense to you or you suspect that misinformation is being spread, *respectfully *ask for clarification or provide facts; don't attempt to ridicule someone because of your lack of comprehension. 

To clarify, I like being able to hear when the turbo spools because then I know for a fact I'm burning more fuel, so I can ease off the gas or shift as soon as I hear it to stay out of higher boost levels. Its another indication I can use to save fuel as RPM alone is not a complete indicator of how much fuel I'm using.


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## XtremeRevolution (Jan 19, 2012)

XtremeAaron said:


> Interested in this write up. Will be looking for it!


Writeup is done. 

http://www.cruzetalk.com/forum/57-how-forum/5479-how-bypass-intake-resonator.html#post73326


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## NickD (Dec 10, 2011)

Its just that while sitting waiting for a red light to turn green, either your instantaneous or average mpg is showing ZERO! In SAE Engineering, talking about a system whereby when your Vss is outputting zero, will automatically turn your engine off, stepping on the gas will start it up again. Without too much discussion on thermal cycling that really wrecks an engine.

Talking about instead of directly driving the AC compressor to switch to a less efficient electrical one, so you don't bake while waiting for that light to change. Also dumping the starter and combining that with the alternator, but this isn't new, Kettering did that in the very first electrically started Cadillac in 1912.

So asking about modifications to save fuel? Is is already being discussed and even done already in some European vehicles, but without the electric AC, claim Europeans are tougher than Americans. Really don't think is is a DIY project, but can switch off your ignition while parked at a light. But will be paying a price with thermal cycling and starter wear.


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## 93Cobra (Feb 13, 2012)

XtremeRevolution said:


> Writeup is done.
> 
> http://www.cruzetalk.com/forum/57-how-forum/5479-how-bypass-intake-resonator.html#post73326



Thanks!! I will try this and see how it goes. 
As far as the other items mentioned, I am already doing those as well. It is a game to me for squeaking out the best possible mpg. On my trip, I drive 1.5 miles of "off-highway" country roads and then get on to the interstate for 38 miles. The interstate trip is 1/2 65mph (posted), and 1/2 60mph (posted). I get on, and set cruise at 68 so I don't get run over, and then the next freeway has cruise set at 62. Also, note that the car never downshifts for any change in grade. There are sporadic stoplights on the 62mph stretch that get triggered when side road traffic wants to get on the freeway. When I accelerate, there is an egg between my foot and the accelerator. The car never goes above 2500rpm. When coming to/preparing for a stop, I put the car in neutral and coast in. This is contrary to a previous post where it mentions not to do that. I have tested this theory and have noticed a definite difference.... my coasting procedure has yielded 34.3 mpg. When I tried the method of leaving the car in gear and coasting in, my mpg dropped to 32.7. I will attack the intake and see if that can increase mpg any more.


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## XtremeRevolution (Jan 19, 2012)

I believe the fuel economy increase in your change between coasting and leaving the car in gear has more to do with external influences than with whether or not you're leaving it in gear. 

I am curious to see what kind of fuel economy you pull after removing that intake duct.


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## 93Cobra (Feb 13, 2012)

Will do, and thanks for all the tips and tricks. I have always used the 'throw it neutral' theory to squeak out the best mpg I could. I do not believe there were any other external influences that would have affected my testing. Weather was similar and there were no differences in traffic/lights/stops. 
In my past, I have driven an AWD Chevy Trailblazer SS to a tad over 19 mpg and used this method of neutral as much as I could. Also, my Cadillac CTS-V is a 6spd manual, and that car runs 21-24mpg using the neutral method (not bad for 550 rwhp!!). I have tried many things on cars to get the best gas mileage I can and it is my opnion that throwing it in neutral to coast to a stop is the best for me. The only vehicle that I do not do that in is a Chevy 1500 4x4 with the 5.3L (cyl. shut off) and the best that truck can do is 17.2mpg.


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## 93Cobra (Feb 13, 2012)

XtremeRevolution said:


> I believe the fuel economy increase in your change between coasting and leaving the car in gear has more to do with external influences than with whether or not you're leaving it in gear.
> 
> I am curious to see what kind of fuel economy you pull after removing that intake duct.


I have not pulled the air intake duct just yet, but my driving habits have increased my overall mpg to 35.79mpg in this 2011 Cruze LTZ automatic. I have also tested the theory of letting the engine slow the car down versus shifting into neutral and coasting in. My test was conducted in the same location, same direction, same weather and the AVG MPG meter was re-set roughly 15 miles prior and had stabilized by the point of the test. This test was conducted on highway conditions. When letting off the gas and letting the engine slow the car down, my mpg went DOWN (per meter). However, when I shifted into neutral, the AVG MPG meter actually jumped up substantially over 4mpg. With this driving style, I am getting around 510 miles per tank of gas. This is EXACTLY why I bought the car and am very happy with it! 
The only downfall that this car has is the cold shifting for the automatic... this is easily fixed by using manual mode, but still sucks to have to do that.


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## XtremeRevolution (Jan 19, 2012)

93Cobra said:


> I have not pulled the air intake duct just yet, but my driving habits have increased my overall mpg to 35.79mpg in this 2011 Cruze LTZ automatic. I have also tested the theory of letting the engine slow the car down versus shifting into neutral and coasting in. My test was conducted in the same location, same direction, same weather and the AVG MPG meter was re-set roughly 15 miles prior and had stabilized by the point of the test. This test was conducted on highway conditions. When letting off the gas and letting the engine slow the car down, my mpg went DOWN (per meter). However, when I shifted into neutral, the AVG MPG meter actually jumped up substantially over 4mpg. With this driving style, I am getting around 510 miles per tank of gas. This is EXACTLY why I bought the car and am very happy with it!
> The only downfall that this car has is the cold shifting for the automatic... this is easily fixed by using manual mode, but still sucks to have to do that.


Nice! That's pretty respectable for an auto Cruze. Glad you were able to squeeze some more out of it.


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## Rogue Sub (Mar 4, 2012)

Guess I need to try my own neutral coast experiment.


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## ErikBEggs (Aug 20, 2011)

93Cobra said:


> When letting off the gas and letting the engine slow the car down, my mpg went DOWN (per meter). However, when I shifted into neutral, the AVG MPG meter actually jumped up substantially over 4mpg. With this driving style, I am getting around 510 miles per tank of gas.


I don't know how this is possible when the car comes with deceleration fuel cut-off. It is basically in neutral anyway when you are off the gas. The injectors are not firing. It is also in neutral at idle as well.


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## sedanman (Dec 10, 2010)

ErikBEggs said:


> I don't know how this is possible when the car comes with deceleration fuel cut-off. It is basically in neutral anyway when you are off the gas. The injectors are not firing. It is also in neutral at idle as well.


It's not in neutral when you're off the gas if the car is moving, it's in neutral when you are stopped. (unless you put it in neutral yourself)


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## tdc (Jan 24, 2014)

There is something I'd like to add: on my previous vehicle, there was a manually actuated valve separating the heater core circuit from the rest of cooling system. I found this advantageous in winter, as, (when closed) the engine came up to temp in less time, as it had that much less coolant to warm up. Once nearing the thermostat set point, I'd open said valve, engine would cool somewhat from the inrush of colder fluid. But by that time, the system was already out of it's 'rich' zone. Also, keeping hot coolant from heater core in summer was an advantage in summer, for obvious reasons. (Said valve was cable actuated from the inside, and was part of the 'temp' lever on the cabin's ambient controls).


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## Alex V. (Sep 20, 2013)

First: Keep your car's drivetrain clean and in tune. It can't be efficient otherwise. Use at least mid-grade fuel. I've seen negligible difference between 89 and 91/93 in my '13 LT stick shift, but 87 to 89 is such a difference I _never _run regular in my car. Boost your tires closer to the max. sidewall pressure - I run my 44 PSI tires at 40-44, rather than the 36/32? recommended on the door sticker. (Note: Under those pressures my original Firestones lasted exactly 50,000 miles, wore perfectly even within .040" or less across the width of all four tires, and helped the car exceed the factory MPG ratings more than a few times.) Be aware of what shape your oil, spark plugs, air cleaner, etc. are in, and if you observe sludge or carbon in the engine or intake do what you can to clean it out. Run a good fuel cleaner through it occasionally (I use Seafoam every 10K, used Amsoil PI last time). And most importantly, learn driving habits that promote economy. Gradual increases and decreases of the accelerator and brakes. Don't cram the gas into the floor out of a light, only to back off once you get up to speed - ease into it only what's needed to gain speed. Others have done more R&D on the intake resonator mod than I have - I currently have the rubber "boot" off of mine but the plastic pipe in; I figure it'll give the air an easier path when vacuum increases but help prevent the junk that gets in the fender cavity from being sucked into the intake. 

That's my humble opinion on "easy/cheap" without getting too carried away.


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## ChevyGuy (Dec 13, 2014)

Alex V. said:


> Don't cram the gas into the floor out of a light, only to back off once you get up to speed - ease into it only what's needed to gain speed.


Excess speed is wasteful, but I'm not so sure as gentle is all that economical. 

It's counter-intuitive, but sometime more power for a short burst is more energy efficient then using less power but longer. I'd suggest that the shorter the distance in lower gears, the more efficient you'll be. And that translates to a pretty brisk clip.

Why does higher acceleration minimize a car's fuel consumption?


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## ssnscruzeeco2015 (Dec 29, 2014)

It is all about RPM - Revolutions Per Mile, the faster you get to 6th gear the less revolutions overall, less you burn. WRT acceleration I avoid going into open loop mode on AFR, I think if somebody has access to the BSFC chart one could notice that the sweet spot likely very large compared to other engines.


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## NickD (Dec 10, 2011)

One cheap mod is to put a wood block under the gas pedal.

Really was surprised when we made a 380 mile trip a couple of weeks ago averaging 38.5 mpg using winter gas. Some city driving in Milwaukee, but mostly the interstate driving 72-75 mph.

2012 2LT with a MT, car is stock, keep the spark plugs and air cleaner clean, 30 psi in the tires. Tried more, just wrecking my suspension and back with all these pot holes. Only use ethanol free 91 octane gas. 

Ha, drive at 60 mph, would get run over by trucks or cause a traffic jam, just kept up with traffic. Many times the traffic was moving at 80 mph. Like to keep my distance from other vehicles, so just kept up.

Last summer with summer gas, quiet road, on a 400 mile trip, set the cruise at 60, averaged 46 mpg. Use Mobile one dexos oil 0w-30 and change at 20% oil remaining. Time to replace the spark plugs, have new ones, 44K miles is enough, starting to get a very slight hesitation when taking off in first gear. Engine talks to me, hey, I need new spark plugs. Do clean them every 15K miles, and toss a can of Seafoam in a full tank of gas every 5,000 miles to keep that engine clean. 

I also have a spare tire.


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## boneheaddoctor (Dec 10, 2014)

Always drive downhill with the wind at your back.


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## Alex V. (Sep 20, 2013)

I'll agree, at least in part, on acceleration. Too sluggish and you're just wasting time in lower gears. The Cruze will pull some awesome numbers putting along at 50-55 MPH, but I have been in situations where my DIC read an increase in mileage even after stints of keeping up with 80-85 MPH traffic. I'm sure the primary factor there was having the wind from the throng of other drivers carrying me along and covering 15% more ground at the same time.


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## obermd (Mar 3, 2012)

I've seen 70 MPG at 70 MPH running with a convoy of semis. Didn't need to tailgate them but just got into the line with them.


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## ssnscruzeeco2015 (Dec 29, 2014)

obermd said:


> I've seen 70 MPG at 70 MPH running with a convoy of semis. Didn't need to tailgate them but just got into the line with them.


Well in that case you would be a hole in 70 MPH air. 

I stay at least 4 seconds behind those guys when I met them. The drivers tend to convert large animals into speedbumps without so much as a tap on the brakes.


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## txcruze26 (Jul 7, 2015)

I'm only averaging 26mph, but I only drive my 14 cruze auto about 15 miles per day, as my job is only 8 minutes away.

Last 3 fillups

93 Octane- 320 miles to E 14.11 gallons $28.50

93 Ocatane- 345 miles to E 13.91 gallons $28.50

93 Octane- 347 miles to E 13.7 gallons $30.00


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## obermd (Mar 3, 2012)

ssnscruzeeco2015 said:


> Well in that case you would be a hole in 70 MPH air.
> 
> I stay at least 4 seconds behind those guys when I met them. The drivers tend to convert large animals into speedbumps without so much as a tap on the brakes.


Definitely driving through a wind tunnel created by the big boys. I like to leave two full rig lengths between myself and the semi in front of me just so I can dodge any road gators they give birth to.


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## jsusanka (Jan 31, 2011)

GoldenCruze said:


> I have to say something about tire pressures.
> 
> A couple of people are flatly stating that the pressure should be 35psi. My Cruze LT has 30psi on the door tag. So what I want to know is what the door tag says for other trim levels. And also what tire and wheel size is on the car. I know that a 17inch size is available in some cases, and there are also the LRR and 'standard' tires as well. So it very well could be that there are different pressures called for between them all.
> 
> ...


My manual and door tag say 35. I always keep them a few pounds over on all our cars so I don't have to fill them all the time as they go down with cold weather. Just lazy.


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## jsusanka (Jan 31, 2011)

NickD said:


> Twelve years ago, the DOT came into our city, did an evaluation, installed over 30 traffic lights, most with no right turn when red, dumped all the yield signs and replaced them with stop signs, and reduced practically all the speed limits. We have three major state highways running through town, rather than bypassing the city, tore down buildings and put major expressways down the middle. City hired a civil engineer to program all of the traffic lights, didn't know what he was doing, could spend ten minutes at a traffic light that was red to make a now forced left turn with not a soul in sight. Plus added hundreds of street lights, city is brighter at night than in the daytime. All at a time when energy costs are skyrocketing.
> 
> Year later, 9/11 came along, more than doubled the size of our police department with three new undercover cop cars. With nothing else to do except issued tickets. Got so bad, city had to elect a judge to hand the fines. Then came ethanol in gas. Takes an extra 15 minutes to cross town, engine spends more time idling than anything, solution, hybrid vehicles that really don't work in cold weather, and only work if you can coast a mile before stopping. Everyone is so impatient, can't do that.
> 
> ...



Couldn't agree with more Nick. Our stop signs make no sense where we live either and waste a ton of fuel. We now have left turn yellows. If you are at stop light and in the left turn lane you no longer get a green arrow but a yellow arrow. You now have to wait for the on coming traffic to go by before you turn. You NEVER get a green arrow. So if there is ton of traffic and you could never go you could be sitting at that light for two or three cycles. This is insane. Are we just changing things cause that department got a budget and needed to spend the money. Makes no sense.


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## jsusanka (Jan 31, 2011)

XtremeRevolution said:


> I believe the fuel economy increase in your change between coasting and leaving the car in gear has more to do with external influences than with whether or not you're leaving it in gear.
> 
> I am curious to see what kind of fuel economy you pull after removing that intake duct.



When the weather warms up and I get more energy I am going to do this mod. I wish I have done it sooner but oh well. The cooler air in the intake could only help. Don't really see it hurting anything.


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## mechguy78 (Jun 6, 2016)

From prior experience, at least with the MT, I have seen as much as 3-5mpg increase by leaving it in gear when coming to a stop. This is due t the dfco programming,in which the wheels are turning the engine over without the use of fuel. Other things that I have done include increased tie pressure, free flowing intake, free flowing exhaust, high voltage coils, low resistance plug wires, and oversized tires. Though the biggest factor is driving habits. My first sunfire consistently got 40 mpg, with opened up intake, exhaust, oversize tires, and increased pressures @ 62mph. My best tank with the Cruze was 3 weeks ago @ 47.6 mpg with tires @ 41psi and the KNN CAI, and a lot of disciplined driving. I am currently looking for 50+ once I get my exhaust done.


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## obermd (Mar 3, 2012)

mechguy78 said:


> From prior experience, at least with the MT, I have seen as much as 3-5mpg increase by leaving it in gear when coming to a stop. This is due t the dfco programming,in which the wheels are turning the engine over without the use of fuel. Other things that I have done include increased tie pressure, free flowing intake, free flowing exhaust, high voltage coils, low resistance plug wires, and oversized tires. Though the biggest factor is driving habits. My first sunfire consistently got 40 mpg, with opened up intake, exhaust, oversize tires, and increased pressures @ 62mph. My best tank with the Cruze was 3 weeks ago @ 47.6 mpg with tires @ 41psi and the KNN CAI, and a lot of disciplined driving. I am currently looking for 50+ once I get my exhaust done.


In our fuel economy forum are some stickies on how to improve your fuel economy. There's one there that I wrote specifically for the ECO MT but some of those same tips should also help the LT.


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## NickD (Dec 10, 2011)

Another factor is passenger mpg, big guys think about this. Like in my motorhome can seat 12 people, and another 8 could sit on the floor for a total of 20. Averaging 15 mpg that translate to 300 mpg per passenger. If I got rid of all the junk inside and installed school bus type seats, could haul 50 for more like over 700 mpg per passenger.

Cruze can only hold five, maybe the best you could do would be like 150-170 passenger mpg.

In aircraft, those sticking up rivets slowed planes down, so went to flat, keeping your Cruze clean with a good wax job may help.

Cost per a gallon of gas is really is not as important as cost per mile, ha, have people tell me I should be using cut rate gas, and save a few cents, they are not very bright, costing a lot more than cost per mile.

Keeping your spark plugs cleaned with the smallest possible gap can sure make a difference, getting 100K miles off a set of plugs is pure BS. Still burning conductive carbon, longest I will go is about 15K miles using only top tier gas and dumping in a can of Seafoam in a full tank of gas every 5K miles.


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