# Not one to typically worry about MPG but 100 mile trip part 1



## 15cruzediesel (Sep 30, 2019)

Yesterday I took a 100 mile round trip and thought I would try to maximize the fuel mileage or at least drive it easy.

Ideal conditions.
85 degrees.
No wind
All five windows open.
A good mix of speeds from 55 to 70.
Cruze control for 95% of journey.

Sad GM didn't push this car harder.


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## Ma v e n (Oct 8, 2018)

You took a 100 mile trip yet show the 25 mile average. Cool story. I can approach 50mpg on my 25mi trip, on a has Cruze.


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## Diesel4Ever (May 30, 2018)

The 25 mile average is the least accurate setting in the DIC. On a full tank of fuel I find that my hand calculated MPG is very close to the 500 mile average.


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## Rivergoer (Mar 30, 2017)

Nice job @15cruzediesel Agreed, the Gen 1 CTD was GM’s best-kept secret. 

1,024 miles on a single fuel-up.


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## Mark cruze diesel (Oct 3, 2019)

Rivergoer said:


> Nice job @15cruzediesel Agreed, the Gen 1 CTD was GM’s best-kept secret.
> 
> 1,024 miles on a single fuel-up.
> View attachment 287342
> ...


That pretty good mpg. Is your car stock? I thought you could get more than 55 mpg in a gen 2 diesel cruze


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## Rivergoer (Mar 30, 2017)

Mark cruze diesel said:


> That pretty good mpg. Is your car stock? I thought you could get more than 55 mpg in a gen 2 diesel cruze


Gen 2 does get better mpg but smaller fuel tank so shorter range per fill-up.


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## MRO1791 (Sep 2, 2016)

15cruzediesel said:


> Yesterday I took a 100 mile round trip and thought I would try to maximize the fuel mileage or at least drive it easy.
> 
> Ideal conditions.
> 85 degrees.
> ...


Good numbers, and it might have been better windows up with A/C when at highway speeds. Mythbusters did a comparison test on MPG with highway, A/C on windows up, and A/C off windows down, and found that the drag from windows burns more fuel than the A/C. I always enjoyed watching that show when they took on such useful items.


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## MRO1791 (Sep 2, 2016)

Mark cruze diesel said:


> That pretty good mpg. Is your car stock? I thought you could get more than 55 mpg in a gen 2 diesel cruze


Since I have both Gen 1 and Gen 2 (and manual and auto for Gen 2). I have some good data. Gen 2 is consistently better.. it's a smaller engine, and the car is an easy 500lbs lighter, I think a bit better on drag as well. I've had 25 mile averages over 70MPG, and best 50 mile is about 69MPG in the Gen 2. Interestingly, the manual and auto on Gen 2 seem to be really close to the same overall, that 9sp auto has a lower final drive ratio than the 6th gear of the manual, and it seems to help highway MPG enought to make up for the pump loss of the transmission. I'd say generally the Gen 2 at the highway gets about 10MPG better than Gen 1, and the city is maybe about 5 MPG better. 
(If you look at my profile picture you will see the 3 Gen 2 Diesel Cruzes, and just beyond the white car, the dark blue Gen 1 Diesel Cruze. at one point I had 2 Gen 1's but traded it for one of the Gen 2s for my wifes primary car.)


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## 15cruzediesel (Sep 30, 2019)

Diesel4Ever said:


> The 25 mile average is the least accurate setting in the DIC. On a full tank of fuel I find that my hand calculated MPG is very close to the 500 mile average.



So got the manual out and didn't realize it has other mile settings, lol.

It is corrupted now with a few all city mikes but as I said I really don't care about mileage that much.

It unusually goes about 600 to 650 miles between getting fuel on about 15 gallons, roughly. Depends on how much city I do.

Next time I will use the 500 mile average for y'all or would the 50 miles average be better for a 100 miles?

I forgot to post the pick of the 500 mile.


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## 15cruzediesel (Sep 30, 2019)

Rivergoer said:


> Nice job @15cruzediesel Agreed, the Gen 1 CTD was GM’s best-kept secret.
> 
> 1,024 miles on a single fuel-up.
> View attachment 287342
> ...


I got some work to do,lol.

Some crazy MPG.


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## Diesel4Ever (May 30, 2018)

About 39-40 MPG is Normal for a 500 mile or hand calculated average MPG on a stock Cruze CTD in my experience. The more freeway % the higher the average will be. The shorter 25 and 50 mile averaging in the DIC over-exaggerates coasting and may also miss a Regen cycle as well. 

I replaced my stock wheels with some 18”s and 225/50R18 Z rated tires and it killed my MPGs by about -10%. Only added 2-3 lbs per wheel but it made a dramatic difference. Kinda wish I didn’t get these wheels although they look great.

if you could find some lightweight 15 or 16” wheels and tires with stock or slightly increased tire diameter you may be able to get a 10% increase In MPG by reducing the unsprung wheel weight.




15cruzediesel said:


> So got the manual out and didn't realize it has other mile settings, lol.
> 
> It is corrupted now with a few all city mikes but as I said I really don't care about mileage that much.
> 
> ...


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## HeathenCruze (May 11, 2020)

Im sure I can easily do a 25 mile average over 50. This is my daily commute, 5 days a week. A good mix of curvy 2 lane country, hiway and about 15 miles of city. Glad someone on here told me to do the math because my DIC consistantly reads 5 or so mpg's low. I did 50mpg running 5 over the speed limit and easy driving on hills and stoplights.
This is the ONLy reason Im driving a cruze. Lol


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## MP81 (Jul 20, 2015)

Diesel4Ever said:


> I replaced my stock wheels with some 18”s and 225/50R18 Z rated tires and it killed my MPGs by about -10%. Only added 2-3 lbs per wheel but it made a dramatic difference. Kinda wish I didn’t get these wheels although they look great.
> 
> if you could find some lightweight 15 or 16” wheels and tires with stock or slightly increased tire diameter you may be able to get a 10% increase In MPG by reducing the unsprung wheel weight.


Going between the 18x8s MSRs (225/40) and the 15x6s steelies (195/60) on the Cobalt absolutely makes a noticeable difference - with the steelies, you can just feel the car accelerating quicker. However, it doesn't hook nearly as good, nor does it have the lateral grip or the lack of sidewall roll of the 18s, so the tradeoff is overwhelmingly in favor of the 18s. Tire spin at 45mph _is_ hilarious, though.

Likewsie, I run a 15" wheel on my Volt for winter (with a 205/65 winter tire) instead of the 17" stock wheels (215/50), and it's immediately noticeable that they're 1.5lbs lighter per corner.

In regards to the 1st gen CTD: good luck fitting a 15" or even 16" wheel - I know there is one or two 16" steelies that'll fit, so _maybe_ a 16" alloy could fit, but a 15" wheel definitely won't clear the large front brakes.


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## Diesel4Ever (May 30, 2018)

Tire rack says these will fit our cars. At 16.8 lbs each vs. 24 lbs each for the stock wheels would make a huge difference by the weight reduction of 7.2 lbs per wheel. Matched with some 225/60R16 tires would make it + 1.2% in total diameter.

This should make a significant improvement over the original Fuel Economy average MPG. Anybody wanna try them out?


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## MP81 (Jul 20, 2015)

Hmm, interesting if they fit or not. I'd probably go with a 215/60R16, in the interest of being lighter and keeping the same section width.


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## Sperry (Aug 3, 2013)

This car is a real highway star . My 50,000 mile average was 49.7 I do believe. I have the pic somewhere. Should be in my signature


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## Sperry (Aug 3, 2013)

About 230,000 miles now and replaced the def heater once . I’d love to get the gem 2 but retirement is getting close and I don’t really need another payment


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## Sperry (Aug 3, 2013)

Best tank for distance . Should have pushed another 50 miles


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## HeathenCruze (May 11, 2020)

Diesel4Ever said:


> Tire rack says these will fit our cars. At 16.8 lbs each vs. 24 lbs each for the stock wheels would make a huge difference by the weight reduction of 7.2 lbs per wheel. Matched with some 225/60R16 tires would make it + 1.2% in total diameter.
> 
> This should make a significant improvement over the original Fuel Economy average MPG. Anybody wanna try them out?
> 
> ...


What are they and how much?


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## Scott205 (Aug 11, 2016)

15cruzediesel said:


> All five windows open.
> A good mix of speeds from 55 to 70.
> Cruze control for 95% of journey.
> 
> Sad GM didn't push this car harder.


First off opening your windows above 35mph defeats the entire slipstream of the car, above 50 it is more efficient to run your a/c. Also cruise control, wastes tons of gas, you don't accelerate much down hill and the computer tend to push the throttle in the 2/3-3/4 going up hill.

When you do it again, especially below 80 degrees, do it will the windows up and your foot keeping the same throttle position (slowing down up hill, speed up down hill) and see what you get.

I wish I would have bought a diesel, but my expectations at the time were to put 9k a year, ended up at 16k due to the ex moving.


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## Diesel4Ever (May 30, 2018)

HeathenCruze said:


> What are they and how much?


Enkei J10

$135 per wheel.



https://m.tirerack.com/wheels/WheelCloseUpServlet?target=runWheelSearch&initialPartNumber=40967003SML&wheelMake=Enkei+Performance&wheelModel=J10&wheelFinish=Silver+w%2FMachined+Lip&showRear=no&autoMake=Chevrolet&autoModel=Cruze&autoYear=2014&autoModClar=Turbo+Diesel


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## boraz (Aug 29, 2013)

Scott205 said:


> First off opening your windows above 35mph defeats the entire slipstream of the car, above 50 it is more efficient to run your a/c. Also cruise control, wastes tons of gas, you don't accelerate much down hill and the computer tend to push the throttle in the 2/3-3/4 going up hill.
> 
> When you do it again, especially below 80 degrees, do it will the windows up and your foot keeping the same throttle position (slowing down up hill, speed up down hill) and see what you get.
> 
> I wish I would have bought a diesel, but my expectations at the time were to put 9k a year, ended up at 16k due to the ex moving.


this car wastes zero gas

this car gets better mpg using cruise control


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## HeathenCruze (May 11, 2020)

Scott205 said:


> First off opening your windows above 35mph defeats the entire slipstream of the car, above 50 it is more efficient to run your a/c. Also cruise control, wastes tons of gas, you don't accelerate much down hill and the computer tend to push the throttle in the 2/3-3/4 going up hill.
> 
> When you do it again, especially below 80 degrees, do it will the windows up and your foot keeping the same throttle position (slowing down up hill, speed up down hill) and see what you get.
> 
> I wish I would have bought a diesel, but my expectations at the time were to put 9k a year, ended up at 16k due to the ex moving.





boraz said:


> this car wastes zero gas
> 
> this car gets better mpg using cruise control


On the 17 mile, 2 lane, 50mph, hilly/curvy section of road I drive twice a day as part of my 170 daily commute...i most definitely get better mileage without the cruise control set. I dont try to maintain the same speed to the top like the cruise does. Pick up a little more going downhill.


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