Highway Range & MPG

[turbomike]

This trip was out in west Texas (fairly flat) running 75 without A/C. DIC indicated 21.6 avg. At fillup, 18.9 gal, 404 mi, 21.4 MPG.

http://i230.photobucket.com/albums/ee291/turbomike87/RainierRange.jpg

[Nukedog]

Nice mpg. I get 19.x with a/c at 72mph in my 5.3 with 3.42's...

[timg]

Nice. I think the highest mileage I've seen was 23 mpg doing 70 on back highways in Nebraska/Kansas. Unfortunately, it's more like 17-18 mpg on a daily basis.

Tim

[Dave]

I usually get 20-21 with the A/C blowing and with 3.73 gears crusing at 75mph. (No winds)

[superman_79065]

Yeah, that is about right. Although, I got 28 mpg between Albuqerque, NM and Amarillo, TX with a good tailwind a couple of years ago....I was surprised!

[turbomike]

Yeah, that is about right. Although, I got 28 mpg between Albuqerque, NM and Amarillo, TX with a good tailwind a couple of years ago....I was surprised!

Yeah... but we have 2 more cylinders.

[superman_79065]

Yeah... but we have 2 more cylinders.


oops.....I didn't look at your engine sizes....nice mpg!

[bartonmd]

The last "actual" trip we took with the TB was when it had 3,000 miles on it (it's got just over 6k on it right now), but we got 19.5 or so with the cruise set at 75mph, with the A/C on. She pretty consistantly gets 15.5 - 16.5 commuting (mixed driving, mostly out in the country, then city for a couple miles).

'07 SWB TB, 5.3L, 4x4, G80, 3.42 gears.

Mike

[Denali88]

Originally i was getting 16 MPG city and 20 MPG Highway but since i had the dual exhaust done the city mileage is 17 MPG and the highway increased to 22 MPG, this isn't nevada or arizona this is new york...

[turbomike]

Originally i was getting 16 MPG city and 20 MPG Highway but since i had the dual exhaust done the city mileage is 17 MPG and the highway increased to 22 MPG, this isn't nevada or arizona this is new york...

MY highway mileage went down about .5 MPG when I installed the 18's with 255/55's since they are .5' shorter and a little heavier than stock and the 3.73's hurt a little also.
Your mileage is great since it's a 4x4.

[nowgrn4]

Worst 19.4,best 21.8@70-73 MPH,AC on.The 21.8 was on I-75 heading south in Tenn. with cruise off.

[ground0ero]

Back in the summer I bought an 06 Envoy XL Denali 4x4 for a family hauler and the truck gets terrible gas mileage in the city. I actually live in a suburban location so much of the driving is done on long back roads, which i thought would be good for improved mpg. The truck is perfectly aligned and has new tires which are inflated properly. Even when I BABY it, the best i'm seeing is 13. Godforbid I actually push the gas down to pass someone, i can actually see the needle move towards E. I realize its a 5.3 but I had an '85 Suburban with the 5.7 before there was fuel injection and DOD and THAT got similar mileage. I noticed that the engine temp is around 210, sometimes a tick higher. Is that normal for this motor? Any idea's for improved MPG's? These $80 a week fill ups are brutal! :suicide:

[Nukedog]

Can't help you on the MPG - i get 16.5 combined with mine and i drive somewhat aggressive.

These $80 a week fill ups are brutal

Mine takes $64 to fill up - why is yours so much???

[ground0ero]

I typically run it down to the bone...due to laziness. The gas stations around where i live are about $3.11+/- for regular. It usually runs mid to high $70's for a top'ed off fill up.

I can't get close to 16 in the city. I just can't seem to figure it out. Do you run premium grade fuels in your truck or 87?

My wife was driving it last week and it checked to computer mpg's and it said 10.5. I asked her if she was drag racin' after dropping the kids off at school. Who knows.... it's a bangin' truck so I'm really not loosing sleep over it. I knew it was a guzzler going in. :sleepy:

[Nukedog]

$3.11 a gal x 22.6 is not $84... It is $70.286

I use 89 in everthing i own pretty much and i only use Chevron, Shell or Amoco...

[ground0ero]

#1 - I never said anything about $84.
#2 - Mine is an XL which = 25 gallon tank.

$3.11 x 25, no wait 24 (I'll give it a grace gallon) = $74.64
depending on fuel prices fluctuating to the 3.20's, it was nearing $80. (and that was running 87)

I'll try 89 for a couple weeks, see if i get any improvement. Thanks!

[BLAZEN03]

I'm at 212 for the first half tank with 5 passengers & the a/c on in the hot summer days...:thumbsup:

[Nukedog]

These $80 a week fill ups are brutal! :suicide:

For posterity...

You didn't say..what? I was of by $4 when i referenced you in the upper thread.

They must have changd the TB's then - my 06 never holds more than 21gal even when the light has been on and below E for 20 minutes or so and my owners manual says 22.6 gal...:undecided

It's all good and i get your point...

[Nukedog]

You need to take your TB to the dealer to see what is up. I just filled mine up and it was below "E" for at least 15 minutes before i did. It took 20.82 gallons @ 3.19per and i had driven 354 miles.
That is combined (almost identical half highway /half city with lots of lights and traffic) at 26 miles 1 way to my work and i averaged 17.0028 mpg with a 5.3 and 3.42 gears i also have a CAI and a 89 octane tune from PCMforless...

[ground0ero]

its due for inspection this month so I'm going to bring it to their attention. Let me ask you, what temp does your TB run at? I feel like my Envoy runs too hot....Circa 220.

17 mpg is great mileage for a V8. Hoping I can report back with a solution.

[Nukedog]

My mileage has gone up since i went over 15,000 miles by about 1mpg city / 2 mpg highway so i am very surprised by it. My temp runs at 12 oclock position so it is near 210.

[ground0ero]

I've got 29,000 on mine. My temp runs about 12 o'clock as well, sometimes a bit over. We'll see...

Thanks for the input.

[Nukedog]

Hopefully it is just a faulty IAT and they can fix it...