Hey GM, where's my 19mpg?!

[Armycop]

Okay, gotta :cuss: for a minute. My 08 Yukon SLT 4wd just touched 10k, did my first oil change at 7k (5qts 5-30), and I have yet to see the advertised 19mpg highway. My commute is 30miles of highway twice a day! I've tried different fuels, even ethanol (not again), and the best I've gotten is 18.1mpg. I've tried 70mph, drafting, ranging between 70-75mph; nothing gets it up any higher! Tires are at 38psi when warm. Is it me, or is GM being optimistic with their mileage figures?

 

[JD Larue]

GM's estimate is ALWAYS optimistic and sometimes they just flat out lie. 18.1 isn't all that bad. That's the kind of mileage I got with my 07 Tahoe for short 30-70 mile drives. I got 18.9 going up to Reno and 23 on the way back. The reason for the better mileage on the way back? Hell, who knows. Alot of it is downhill is the only reason I can think of. But 18 with a 4x4 SUV is better than I ever expected. I had an 03 Hummer before my Tahoe and it got 10.3 no matter what I did. So for me...18 is pretty damn good. Don't expect alot more than that brother.

 

[Gambler]

I've found the best mileage is obtained around 60mph.

 

[bad63lac]

I do 65mph on the highway for 75 miles to work (in my Suburban). I get anywhere from 20.5 to 22.5 mpg every single day.

I use cruise control almost the whole way. Makes a big difference.

You can't expect to get better than 18 if you are doing 70+mph especially if you have your foot on the accelerator.

 

[aaron72]

I average about 19.3 in combined city/highway driving, so 19 on the freeway is easily achievable. Just need to be less of a lead foot.

 

[DownTownDru]

For my 07 4x2 Tahoe, the difference between 65mph and 70mph is about 1.5mpg. BIG DIFFERENCE. Wind speed and direction are also a huge influence.

A J

 

[Ed Blown Vert]

For my 07 4x2 Tahoe, the difference between 65mph and 70mph is about 1.5mpg. BIG DIFFERENCE. Wind speed and direction are also a huge influence.

A J

I normally drive 70, but tried it today at 65. There is a difference. I stayed in V4 mode longer and Instant MPG was 25~

 

[Yukon Joe XL]

I always chk MPG on fillups but i'll be damned if i'm gonna drive 65 for better gas mileage:lol: My Yukon has just over 2K on it now and I hope it gets better as it is broken in but I only get about 11/15 now. Tried E85 and regular gas and the difference seems to be about 1.5 MPG.

 

[LVYUKYUK]

I always chk MPG on fillups but i'll be damned if i'm gonna drive 65 for better gas mileage:lol: My Yukon has just over 2K on it now and I hope it gets better as it is broken in but I only get about 11/15 now. Tried E85 and regular gas and the difference seems to be about 1.5 MPG.

My mpg has been increasing over the last few tanks. I'm at 3,100 miles and just switched to Mobil1. Hopefully, I can squeek out another mpg or two, but if it does not happen, then I'm okay with just the extra protection.

 

[Ed Blown Vert]

I always chk MPG on fillups but i'll be damned if i'm gonna drive 65 for better gas mileage:lol: My Yukon has just over 2K on it now and I hope it gets better as it is broken in but I only get about 11/15 now. Tried E85 and regular gas and the difference seems to be about 1.5 MPG.

There is no way I would drive 65. Just had to see.

But thanks for making me feel better about getting a Hybrid.

I am pretty sure once you get more miles, it will get better.

 

[Gambler]

The gears that you have will make a big difference too.

 

[RenegadeTahoe]

Okay, gotta :cuss: for a minute. My 08 Yukon SLT 4wd just touched 10k, did my first oil change at 7k (5qts 5-30), and I have yet to see the advertised 19mpg highway. My commute is 30miles of highway twice a day! I've tried different fuels, even ethanol (not again), and the best I've gotten is 18.1mpg. I've tried 70mph, drafting, ranging between 70-75mph; nothing gets it up any higher! Tires are at 38psi when warm. Is it me, or is GM being optimistic with their mileage figures?

GM does not create the EPA estimates, the EPA does. Fuel mileage has a lot of dependencies. Temperature, elevation, A/C, load, passengers, driving style, gearing, speed, etc. all play a HUGE role in your actual mileage. Light-footed driving will net you better fuel mileage, so will cruising at lower speeds. Driving downhill vs. uphill (even a small incline / decline) will all effect it. My 2006 Honda CR-V was rated at 23/29... average city / highway was 21... I NEVER saw anything NEAR 29.... but my driving style was a big factor (or should I say my WIFE's. :shhh: ) My Tahoe is rated at 12/16, I've gotten 18.9 highway and 15.1 combined, however I've also filled up at 10.5MPG as well.

 

[ugachs24]

My '04 LT usually gets 1-2 MPG better than my '08 Z71 even though they have the same gearing and everything, but last week I got 21.6 going 65 between Tampa and Fort Lauderdale, it was crazy. I had never gotten more than 19 in the Z71 so I was pumped. It both have around 40k miles.

 

[cbramsey]

My 2008 LT1 2WD gets between 18 and 19 in mixed city/highway driving. If I am doing highway mileage only, I get 21ish. I am driving 60 - 65 using cruise control.

Hope this helps.

 

[73shark]

A/C will cost you 1-2 mpg. Wind is also a big factor.

FWIW I get about 12 in town on mostly short trips and 17-18 on long trips at 70 mph. best tank was 19+ at ~60 mph. All actual calculations and 3.73 gears. I hear that the 4.10 gears do better. Counter-intuitive but something about the 5.3 sweet spot.

 

[quikag]

I got a true 20mpg from Dallas to Austin and 21mpg from Austin back up to Dallas this past weekend in my '08 Denali with the 6.2L motor. That was driving between 65 and 80mph the whole way using light throttle. I was really surprised in a good way.

I would recommend slowing down a bit more and using cruise control exclusively. You'll get your mpg if you work on it.

 

[Don DePontee]

With my 08 2WD LTZ 5.3 flex fuel V8-V4 and lowered 2" I get 21.5 to 22 mpg on the highway running at 65 to 70 mph with the AC off. With the AC I loose 1 to 1.5 mpg. Around town driving drops to the 15 to 16 mpg range
Don

 

[jlcvt]

If you’re worried about gas mileage keep it around 55 - 60 mph range. That’s supposedly the area where an engine is most efficient. The use of cruise control will help keep your foot off the gas and only increase your speed when needed. Ethanol will not help your vehicle get better mileage. The figures for city / highway are not written in stone, there are too many variables for them to be accurate 100% of the time. Besides 18.1 isn’t that bad for a vehicle as big as a Tahoe.

 

[fco_gonzo]

18 MPG is Great! I get 10 mpg in the city and 13 MPG highway! before the lift I averaged 17-18 MPG also.

 

[mlwald79]

lol. i'm getting 11.8 in my brand new denali, pretty much all city driving. i'm sure the 24s aren't helping either.