# Diesel MPG



## trevor_geiger (Nov 29, 2012)

Very nice numbers you got sir, how are you liking the diesel so far?


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## CruzeTD (Jun 1, 2013)

It's awesome got the windows tinted and the more this motor breaks in the better it runs. With the MPG as high as it is it makes the Harley not as economical as it used to be. I get about 56 mpg with the bike on the highway. 


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## rmass09 (Apr 17, 2011)

Like how it says "Best Score" Makes it into a fun game


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## obermd (Mar 3, 2012)

I'd keep the Harley. It's definitely more fun than the Cruze.


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## jblackburn (Apr 14, 2012)

Not bad at all, especially considering those speeds!

What RPM are you turning @ 80?


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## rescueswimmer (Mar 28, 2013)

Chevy needs a new flash for the eco and diesel DIC best Scores, both of mine are well over the 50+ MPG and the 500 mile one is sitting at 45 mpg.


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## obermd (Mar 3, 2012)

rescueswimmer, I completely agree that the 2011 and 2012 ECOs need a flash to show numbers above 50 MPG, as long as it doesn't take away my digital water temp readout. Also, all Cruze trims should have this display, not just the ECOs.


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## H3LLON3ARTH (Dec 16, 2011)

obermd said:


> rescueswimmer, I completely agree that the 2011 and 2012 ECOs need a flash to show numbers above 50 MPG, as long as it doesn't take away my digital water temp readout. Also, all Cruze trims should have this display, not just the ECOs.


They should have kept thhe water temp readout.

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## obermd (Mar 3, 2012)

CruzeTD, well done. I didn't notice the average speed the first time. Once again the aerodynamic enhancements on the ECO trims are destroying the EPA highway estimates. I would have really hoped that GM would have figured out the adjustment for the ECO package by now, but obviously not.


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## Aussie (Sep 16, 2012)

obermd said:


> CruzeTD, well done. I didn't notice the average speed the first time. Once again the aerodynamic enhancements on the ECO trims are destroying the EPA highway estimates. I would have really hoped that GM would have figured out the adjustment for the ECO package by now, but obviously not.


When these tests are done is wind resistance part of the test or do they just run a dyno with estimates put in?


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## ErikBEggs (Aug 20, 2011)

obermd said:


> CruzeTD, well done. I didn't notice the average speed the first time. Once again the aerodynamic enhancements on the ECO trims are destroying the EPA highway estimates. I would have really hoped that GM would have figured out the adjustment for the ECO package by now, but obviously not.


Don't quote me, but I think the aerodynamic enhancements wouldn't be possible / compatible with the RS package. Hence, why there will never be an RS Eco or Eco-D. The entire front fascia of an RS is different than the Eco. The Eco trims have to incorporate the grill shutter. We have to choose which form of vanity we are after - looks or frugality.



Aussie said:


> When these tests are done is wind resistance part of the test or do they just run a dyno with estimates put in?


Wind resistance and weather conditions are "calculated" using elaborate formulas and load stuff on the dynometer or whatever it is called. Basically a treadmill for car testing


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## jblackburn (Apr 14, 2012)

Meh. I'd chalk this one up to a powertrain design, not aerodynamics. The Cruze models are all pretty aerodynamic with a .28-.31 drag coefficient. Diesel engines are just ridiculously efficient.

If the drag coefficient is a big deal, watch for MPG numbers on the new Mazda3 with a value of .25 (and the SkyActiv engine) and then compare it to last years design.


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## ErikBEggs (Aug 20, 2011)

jblackburn said:


> Meh. I'd chalk this one up to a powertrain design, not aerodynamics. The Cruze models are all pretty aerodynamic with a .28-.31 drag coefficient. Diesel engines are just ridiculously efficient.
> 
> If the drag coefficient is a big deal, watch for MPG numbers on the new Mazda3 with a value of .25 (and the SkyActiv engine) and then compare it to last years design.


They are all pretty efficient but regular Cruzen are 0.31 and Eco are 0.29. That is what.. 7% better aerodynamics. It makes very little difference under 60 mph, but from that point on you bet it makes a difference!! Drag increases cubically with velocity squared or some junk like that I forget the exact formula. Just know it is not a linear progression and ever fraction counts.

The new Mazda will be over 20% aerodynamic than a Cruze. I still could care less because I think it is hideous. LOL


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## 70AARCUDA (Nov 14, 2010)

Drag is V-squared
HP is V-cubed


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## obermd (Mar 3, 2012)

I know the coefficient of drag can be calculated, but does anyone know if GM actually takes a car out on the road to validate the result? Wind tunnel testing is good, but there are more variables than even wind tunnel testing can handle. With the ECO trims consistently coming up with better highway MPG numbers I starting to think our CoD is lower than GM's official value.


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## jblackburn (Apr 14, 2012)

I highly doubt they would under-report the drag coefficient - that was one of their major selling points when the Cruze released in 2011. When you think about it, the Cruze is an old platform that came to us from overseas and was never designed to be terribly aerodynamic in the first place (it was just made to compete with "larger" small-cars overseas), so they took it and made a few major tweaks to it to do the best they could. No one knew that it would become one of the best-selling Chevrolets here - it was a gamble.

As other cars were redesigned solely for the US market that hit similar or better drag coefficient numbers to compete in the fuel-economy war now waging between models, Chevrolet quietly stopped advertising this bit of information. Believe it or not, the Elantra, Sonata, Camry, Civic, FRS all meet or exceed the Eco's drag coefficient of .29. A Prius has a .26 (not a surprise really) and a Mercedes CLA releasing later this year to the upscale small-cars list gets a whopping .23 (!), along with that new Mazda3. The new Cruze model will have to be designed with aerodynamics in mind from the ground-up to compete.

EVERY car doesn't report the true mileage for a constant-speed, highway cruising trip on the window sticker. If Chevy could put 50 MPG on the window sticker for the Eco or the Diesel models, they would - it would be a HUGE selling point. But in the "highway" driving that most people do on their commutes to work or wherever they go day-in and day-out, as modeled by the EPA tests, they do not hit 50 MPG for 70% of the driving conditions. Their tests do, however, show what to expect if you drive with more traffic/stops/accelerations in your highway cycle or more solid-speed highway driving with a range of expected mileage for 13-16% of other commutes.

Please see the EPA test cycles on the post here:
http://www.cruzetalk.com/forum/27-fuel-economy/14764-happy-base-model-cruze-gas-mileage.html

The Cruze as a whole is just an excellent setup for MPG. I and several others here have hit 45-52 MPG on a non-Eco Cruze with steady-state highway driving at a constant speed. Think about it: it's got a lot of things going for it to hit high MPG numbers that are not reflected in dyno tests done in such a short timeframe.

You've got a low rolling resistance across the entire Cruze lineup due to low engine braking and transmission drag. Let off the gas in just about any other car besides a Cruze (even one with a small engine like a Honda Civic) and it slows down dramatically more than the Cruze does on flat ground, and especially on small hills. There's also the engine with smaller displacement than everything else on the road. When not in boost, you're saving a lot of fuel with such a small displacement. Add the Eco aerodynamic package and shorter gearing ratios, and there's another 4-5 MPG at 60-70 MPH over other 1.4T models (drag will play a bigger role as you speed up more).

The ridiculously efficient nature of a diesel engine just adds the icing onto the cake for the Cruze as a fuel-efficient platform. If you take two V8 pickup trucks that are otherwise virtually identical save that one is a gasser and one's a diesel, the diesel will return SIGNIFICANTLY better MPG than the gas one. Ask any Silverado 2500 or F250 driver, especially one that tows heavy loads, and you'll find this to be true. The same is true for VW's, though none of their engines really compare well to the TDI. The 2.5 is more powerful and a 5-cylinder; the 2.0 is a worthless tractor motor that should have been dumped back in 2001.


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## 70AARCUDA (Nov 14, 2010)

Uh, compare the EPA Test Load HP (TLHP) numbers for *50 mph *for the three different Eco Cruze models and draw your own conclusions:

*2013 1.4LT Eco Gasoline(6M)...9.3 hp; test wt = 3250 lbs 
2013 1.4LT Eco Gasoline(6A)..10.2 hp; test wt = 3375 lbs
2014 2.0LT Eco Diesel(6A)....11.0 hp; test wt = 3750 lbs *


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## jblackburn (Apr 14, 2012)

70AARCUDA said:


> Uh, compare the EPA Test Load HP (TLHP) numbers for *50 mph *for the three different Eco Cruze models and draw your own conclusions:
> 
> *2013 1.4LT Eco Gasoline(6M)...9.3 hp
> 2013 1.4LT Eco Gasoline(6A)..10.2 hp
> 2014 2.0LT Eco Diesel(6A)....11.0 hp*


That's what I'd expect. Manual = least power loss.

Auto = more power loss.

Diesel = bigger engine; more friction to overcome. Yet it is more efficient on the road.


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## Blue Angel (Feb 18, 2011)

obermd said:


> rescueswimmer, I completely agree that the 2011 and 2012 ECOs need a flash to show numbers above 50 MPG, as long as it doesn't take away my digital water temp readout. Also, all Cruze trims should have this display, not just the ECOs.


Well, my '12 is still stuck with the 50 MPG cap on the "best score" display and it doesn't have a water temp readout, so don't go running to the dealer with a '11 hoping to get a newer reflash... you'll gain nothing and lose your water temp!

Whoever decided to cap teh display readouts at 50 MPG was a real idiot... this HAD to be some sort of intentional decision as all other readouts go to 99 MPG. Also, they should have put the "infinity" symbol on the instant MPG readouts so you could see when DFCO was in effect. The metric readouts will display 0.00 L/100km when DFCO kicks in, but the US readout only goes up to 99 MPG.

Little oversights like this are things that just make me shake my head... how much time and effort would it take to do a few little details right? You can't tell me that the development guys circling the track working on the Eco didn't notice the display maxing out at 50.0 MPG? Looks like they FINALLY got it right with the TD model...


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## BowtieGuy (Jan 4, 2013)

+1 on the 99 vs infinity symbol for when in DFCO. That would make it really easier for using DFCO.


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## grs1961 (Oct 23, 2012)

Just switch to using sane numbers - the metric "l/100km" drops to an unmistakeable _*0.0*_ when DFCO kicks in.


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## jpm84092 (Jun 23, 2013)

REAL WORLD TEST- I live in the Land of Mountains and Mormons (Salt Lake City), but moved from Wisconsin 4 years ago. I and the wife took a trip to Wisconsin for a family reunion just before the 4th of July. The trip out was basically up and down, but with an overall downhill trend with a cross-wind and occasionally a headwind (no beneficial southwest winds as I drove West). We had ourselves and baggage and the DIC indicated 50.6 mpg, but the fuel receipts versus odometer calculated at 51.9 mpg. The trip back was uphill and I faced the dreaded southwest winds. We were heavy with about 330 pounds of cargo + myself and the wife. (The cargo included some Wisconsin cheese, Wisconsin smoked summer sausage - not available in Utah - and some beverages that are less then 1/2 the price they are in Utah.) The DIC indicated 46.8 mpg but the odometer vs fuel receipt calculated at 48.2 mpg. The total trip odometer vs. fuel receipt for the 2980 mile round trip was 50.0 mpg. Oh yeah, the A/C was on for both legs of the trip as it was very hot in the West and the Mid-West (and very humid in the Mid-West). I only had about 1700 miles on the car when the trip began. The engine is not broken in yet. And, no hyper-mile techniques - no semi-drafting or coasting downhill. This was a real world test with the cruise control managing the throttle all the way (except for leaving the Interstate for fuel, food, or "rest stop".)

I bought my 2014 Cruze CTD over Memorial Day and traded my 2011 Cruze ECO base model. Economically, it may have not made sense, but the creature comforts of the Cruze CTD combined with the fact that it is a torque-monster have led me to not regret the change for one moment. The Cruze CTD tackled the steep mountain passes of Utah and Wyoming without breaking a sweat or downshifting (something impossible in my 2011 ECO). It never overheated in the 105 F temperatures with the A/C on.


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## Blue Angel (Feb 18, 2011)

jpm84092 said:


> The total trip odometer vs. fuel receipt for the 2980 mile round trip was 50.0 mpg. Oh yeah, the A/C was on for both legs of the trip as it was very hot in the West and the Mid-West (and very humid in the Mid-West). I only had about 1700 miles on the car when the trip began. The engine is not broken in yet.
> 
> I bought my 2014 Cruze CTD over Memorial Day and traded my 2011 Cruze ECO base model. Economically, it may have not made sense, but the creature comforts of the Cruze CTD combined with the fact that it is a torque-monster have led me to not regret the change for one moment. The Cruze CTD tackled the steep mountain passes of Utah and Wyoming without breaking a sweat or downshifting (something impossible in my 2011 ECO). It never overheated in the 105 F temperatures with the A/C on.


Very nice, sir! Glad the TD is putting a big smile on your face!

How fast were you driving with the cruise set?


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