21/22 vs 20/23 mpg?

[Green Machine]

Sorry if I seem like I'm obsessing about MPG's, but actually I'm more interested in finding out if there are any major differences between the different model years of HyHoe's.

On Edmunds, 2008-2010 models are listed as 21/22 mpg whereas the 2011 is listed as 20/23. Is there a difference between their engines?

I know since 2008, the newer trucks got adjustable pedals, traffic report capability, more airbags, bluetooth, and a USB audio port, but as far as I know the engine and hybrid system are all the same.

Anyone know more about this? The EPA didn't change the way it determines fuel economy numbers again, did it?

 

[soulsea]

Not sure why the difference in mpg on the 2011 Albert ... it's the same engine and basic options on all those model years so far as I know.

Maybe they programmed the fuel management system and/or the 2 mode system differently to be more efficient under highway conditions and sacrificed a little city mpg. Maybe it more accurately reflects fuel consumption after a couple of years of experience.

Tis a mystery ... can't wait till you solve it.

 

[Green Machine]

This topic has still been sitting in the back of my mind. Still don't have an explanation but I came up with a new question as a result of trying to find an answer.

Which is heavier? The hybrid or the gas version of the Tahoe? I recall someone saying that the Hybrid is lighter but also once read a review on the Hybrid saying it was heavier.

I found these numbers from AOL:
2008 Tahoe Hybrid (2wd/4wd): 5270/5527 lbs
2008 Tahoe (didn't specify 2wd vs 4wd): 5265 lbs

And I found these numbers from the Chevrolet website:
2011 Tahoe Hybrid: 5688 lbs
2011 Tahoe (LS/LT/LTZ): 5906/5931/6029 lbs.

 

[soulsea]

Hybrid is about 340 pounds lighter than regular tahoes.

2011 HyHoe curb weight: 5688.00
2011 LTZ curb weight: 6029.00

I'm pretty sure mine is heavier though.

 

[Green Machine]

Here (Car and Driver) it says a 2008 Hybrid (2wd/4wd) weighs 5650/5850 lbs:
http://www.caranddriver.com/reviews...brid_4x4-first_drive_review/powertrain_page_2

"All the hybrid hardware adds weight—about 350 pounds in the Tahoe's case, GM says—which is not the direction to go to maximize efficiency of an already porky SUV. To counteract this and admirably maintain a 5850-pound weight (5650 for two-wheel-drive models), the Tahoe changes a number of pieces to aluminum: the hood, the front-bumper beam, the driveshaft, and the rear liftgate. It also gets thinner, lighter seats and forged aluminum wheels. Even the recommended tire pressures are bumped up by 2 psi to eke out every last bit of efficiency.

To maximize aerodynamics—trimming the coefficient of drag from 0.36 to 0.34—the hybrid's lower front fascia is devoid of holes and extends closer to the ground to decrease the amount of turbulent air passing beneath the truck, and a roof-mounted spoiler at the rear smoothes airflow over the top. Four-wheel-drive models are lowered 0.4 inch in the front."

Here (Car and Driver) it says a 2007 LTZ weighs 5840 lbs:
http://www.caranddriver.com/reviews...tahoe_ltz-road_test/driving_impression_page_2

Bottom line: All Tahoes are heavy beasts!

 

[domin8]

ECM/CPU?whatever you want to call it??? Did GM change that with the model year change? A newer computer, in theory, might have allowed GM to change some calculations that affected the fuel economy. Just a theory I have since you are asking.

 

[04ctd]

rims & tires make BIG diff too.

skinny 17 is ~6 inches wide,
OEM 20's are prolly 8~10, so for all 4, thats a bit.

the width of the corvette tires was considered a hindrance to top speed, at one time, and look how low it is

i think the C&D article points out that a LOT of very small things make a VERY small difference.

i set the cruise to maximize MPG, it will drop into V4 much faster on cruise than when on the pedal.


we got 18.5 three times on a road trip (SC to NY)
we ran 70~75, CAI & 3 inch catback.
OEM 20's
100k miles on it.

does anyone EVER get 20~22 hand calc'ed?

 

[soulsea]

does anyone EVER get 20~22 hand calc'ed?

Well, considering this is a Hybrid mpg related thread, then yes.

Actually even with 22"s on I still get around 22-23mpg highway at 70mph.