cocodrie55

I've got 2000 miles on an 07 and the gas mileage is a disappointmet to say the least. Running mostly highway miles up to 75 mph, I get in the 16's. The best I got was 17.9 running mostly two lane highway roads at 55 - 65 mph. I noticed that the V8 - V4 indicator only shows V4 when I let my foot off the gas. There is no speed I can get it to stay in V4. This doesn;t seem right and may be the cause of my poor mileage. What should I expect with the V4 mode? I thought cruising on level ground at 65 mph it should be in V4 mode. Any comments, and sorry if this has been beaten to death on another post before. Thanks.

jophilpott

I get avg about 15.8. On the hwy anything under 70 I would say about 17/18 in V8 and 30ish for V4. I live at low elevation, heavy air. I do have an upgraded intake and exhaust so that could make a difference.

tj

I noticed if you keep it around 65 or less on the highway, the average milage will begin to creep up. Best I've gotten is 18.6 mpg and that just about all highway. The V4 mode will only stay on if you are going down hill or running on the flat with virtually no load on the engine. The slightest incline and all 8 cylinders kick in. Every dealer I talked to ranted about the 21 mpg it would get and how much more fuel efficient it was over the Expedition. Bogus!

73shark

Just because the brochure and Chevy website says it'll go into V4 mode at hwy speeds on level roads doesn't really mean that it'll do it. []

The only way I've seen V4 going uphill is in tow mode at 45 mph. To be honest tho, I haven't had a chance to experiment at higher speeds but I know that at 60-70 mph, it won't go into V4. I have about 5,200 mi and get about 14 mpg in town and the last hwy mileage was 16+ but was at about 2K mi. Most posts have indicated that mpg continues to improve up to about 7K. Mobil 1 gave me about 0.5 mpg improvement. Apparently those with the 4:10 gears get better mph because the 5.3 is in a better operating range.

jmitchell

I'm up at the 5000'+ elevation range and only getting 15.9 mpg with a little over 5k miles on it. The V4 mode is definitely not as wonderful of a feature as the dealership will tell you. Like these guys say, it only kicks in when going downhill or coming to a stop. However,I do like the ability to watch how my lead foot effects the mpg and V8/V4 mode on the display. I keep it on this display mode at all times which I believe is most of the reason I get 15.9 mpg and not 13.0 mpg.

How are people doing with the flex fuel option?

didithepest

I drive City(30) And Highway (70) average speed is around 70 and i am gething 11.9 is the best so far ( 9600 miles )

hunter399

I am running E85 with mileage in the 13s....

I got a K&N drop in which might be helping a bit

The awful mileage I get with E85 is offset by the 40 cents per gallon less I pay!

rruelas

I bought my tahoe LT in September 06, but I think it was built on Jan 06. I live in South Texas ( not many hills) and I avg about 15 mpg with city and hwy combined. But I did take a road trip to Orlando and with the cruise set at 70 the whole way, I was able to get 20.5 through TX and LA, but when i got pass MS, It dropped to 19.2. The only thing is that I drove the Tahoe like it was a baby carriage.
I have noticed on my Tahoe, I can get it to stay in V4 if im going slower than 60 and there is no incline. But if you push the gas, even just a hair, it will go to V8 mode. If you have a lead food, or drive much more than 70 you there is no way your going to get better than 17, but if your easy on the gas, you should bet better MPG on the Hwy.

cocodrie55

A friend of mine says his Avalanche can get 20 mpg on the hwy. I just don't see the Tahoe getting that at normal highway speeds and conditions. The 21 advertised is just a crock!

doo600

Are you guys doing the math or going by the computer. I think there is a big difference. My DIC says 17 but my math said a little over 19. Ain't no mountains in the Chicagoland area. though.