00-06 Tahoe MPG poll

[Teamiez]

now that these rigs are getting older and mileage is going up curious to see what the majority of people are experiencing MPG wise for some fun! I think mine was rated 14 city 17 highway and I am seeing a mixed average of pretty much 10-11 winter and 12-13 in the summer. Pure highway high 15’s

 

[nick0789]

2005 Z71, 186k miles; bone stock aside from upgrading to MSD wires during the last tune-up (@150k).

Around town I average 15 +/- 0.5 MPG

On the highway my MPG is dependent on the highway itself. If the speed limit is 55-60 mph I can get 19.5ish, with the addition of Lucas upper cylinder lubricant. If the speed limit is 65+mph I am lucky to see 17 MPG. Life can be rough at 2500+ RPM at these speeds, given the current gas prices lol

 

[Fless]

5.3L, lowest category. Mostly run E85 so it's expected to be less. But the oomph!

 

[Chubbs]

5.3L, lowest category. Mostly run E85 so it's expected to be less. But the oomph!

i drive a 2003 GMC yukon vin Z flex fuel and always curious about randomly fueling up on e85. i bought it used several years ago with a little under 100k and have no idea of what the original owner may have used.

are you to run the regular unleaded fuel nearly empty before gassing up on e85 and vice versa? what’s the harm in mixing fuels at 1/4 or 1/2 tank?

what negative side effects can i expect suddenly switching to e85 fuel?

of course i can read through the owners manual or do a web search (which i certainly will) but want to discuss with 1st hand replies. thanks!

 

[Fless]

There's no harm in switching fuels back and forth as long as it's FF compatible; your 2003 truck has a physical alcohol sensor that tells the ECM to adjust the fuel delivery. Your truck will use more fuel on E85 but should be a bit peppier. Higher percentages of ethanol can cause harder cold weather starts, if you're in that type of climate.

When you change your fuel composition significantly by refilling your tank, the ECU will sense the change if 3 gallons or more are added. What I've read is then it helps to drive it 7 miles without stopping the engine; that way the fuel trims are fully adjusted. That may not be your case since you have the physical sensor (the later models have a "virtual" sensor and may need that time to adjust), and I've noticed that mine adjusts within two or three miles.

And, of course, the amount of ethanol that you're getting from the pump can vary by station and season.

 

[swathdiver]

what’s the harm in mixing fuels at 1/4 or 1/2 tank?

We often run mixes and get better fuel economy than straight gasoline and less cost per mile than full strength E85. My truck likes 16% to 22% or so.

There's no harm in switching fuels back and forth as long as it's FF compatible; your 2003 truck has a physical alcohol sensor that tells the ECM to adjust the fuel delivery. Your truck will use more fuel on E85 but should be a bit peppier. Higher percentages of ethanol can cause harder cold weather starts, if you're in that type of climate.

When you change your fuel composition significantly by refilling your tank, the ECU will sense the change if 3 gallons or more are added. What I've read is then it helps to drive it 7 miles without stopping the engine; that way the fuel trims are fully adjusted. That may not be your case since you have the physical sensor (the later models have a "virtual" sensor and may need that time to adjust), and I've noticed that mine adjusts within two or three miles.

And, of course, the amount of ethanol that you're getting from the pump can vary by station and season.

This! ^^^^

 

[TheAutumnWind]

My 05 Escalade ESV AWD with a 200k mile LQ9 just averaged about 16mpg on a 10 hour trip to and from San Diego. I could probably get it to do 18 mpg highway in ideal conditions. Tends to do in the 11-12 mpg city. Not sure if you want me to skew your poll since its clearly not a tahoe.

 

[Teamiez]

My 05 Escalade ESV AWD with a 200k mile LQ9 just averaged about 16mpg on a 10 hour trip to and from San Diego. I could probably get it to do 18 mpg highway in ideal conditions. Tends to do in the 11-12 mpg city. Not sure if you want me to skew your poll since its clearly not a tahoe.

Hey your 6.0L seems to get the same mpg as my 5.3L...still interesting to know. Only major highway trip I took with my Tahoe was from Buffalo NY to New Haven CT with 4 passengers loaded doing 70+ most of the way I saw a average of 15.8 lol

 

[Chubbs]

We often run mixes and get better fuel economy than straight gasoline and less cost per mile than full strength E85. My truck likes 16% to 22% or so.


This! ^^^^

cool thanks

 

[Redfire Metallic]

My 03 4x4 Tahoe gets 12.5 city sometimes get it up to 13.5. Had another 03 2wd that would get 14-15 city. Had a 02 Yukon Denali that would get around 13.5 city. All of em bone stock, denali was on 22s, both tahoe on 20s