Poor Gas Mileage for Tahoe LT 2008

[George B]

so u recommend using 87 and every 4x or so filling up with e85?

He is recommending putting a mix of 87or 89 and e85 in at each fill-up. If you get the mix right they run well and the mileage is good.

I disagree that they run fine on 87. They run ok and it won’t hurt. I feel the performance on it is subpar and prefer 89 or E85 in my 2013. If you feel it runs fine then go with it.

 

[Bill 1960]

what i am now getting is 13 mpg after figuring everything out. I took out my rear 2 seats, making sure i have 32psi tires, i put in 87 gas from BJ's.

You haven’t said what kind of driving you do. City / highway, flat/hilly, short drives or lengthy ones. Your mileage may be excellent if it’s short city drives, or terrible if you’re driving 55 mph on a flat highway.

 

[Ed Alexander]

I casually drive. So I have a combination of highway and local driving. I have been using 87 gas now for for a while and getting 13mpg steady in the summer. with A/C blasting at 60 degrees. I also just took out the 2x 3rd row seats so that may also get me a little better mileage.
At this time I AM NOT putting e85 into my tank.

 

[Ed Alexander]

For E85 I think i get better gas mileage in the fall/winter but i need to test it as I just got this truck last year.

 

[Leevon]

There is an alcohol content sensor that is finicky. Find someone with the right scan tool to do a re-calibration. There are a couple other re-sets you can do for mileage while you're in there.

 

[Fless]

There is an alcohol content sensor that is finicky. Find someone with the right scan tool to do a re-calibration. There are a couple other re-sets you can do for mileage while you're in there.

Should be a "virtual" alcohol sensor on a 2008; no physical sensor. Alcohol content is re-settable using a Tech 2, but don't do that if your ethanol content is over 10% or so.

 

[alpha_omega]

He is recommending putting a mix of 87or 89 and e85 in at each fill-up. If you get the mix right they run well and the mileage is good.

I disagree that they run fine on 87. They run ok and it won’t hurt. I feel the performance on it is subpar and prefer 89 or E85 in my 2013. If you feel it runs fine then go with it.

Is your 2013 a 5.3l? If it’s the 6.0 or 6.2l that will make a difference in whether or not it runs fine on 87.

For E85 I think i get better gas mileage in the fall/winter but i need to test it as I just got this truck last year.

-When was the last time you changed out your fuel filter? Or did the 2008’s have them built into the tank/pump?

-Have you checked/cleaned the air filter, cabin air filter, radiator/condenser fins, Mass air flow (MAF) sensor?

-Are your radiator baffles in good shape and are your skid plates installed?

 

[George B]

Is your 2013 a 5.3l? If it’s the 6.0 or 6.2l that will make a difference in whether or not it runs fine on 87.


-When was the last time you changed out your fuel filter? Or did the 2008’s have them built into the tank/pump?

-Have you checked/cleaned the air filter, cabin air filter, radiator/condenser fins, Mass air flow (MAF) sensor?

-Are your radiator baffles in good shape and are your skid plates installed?

My 2013 is a 5.3 FLEX motor.

 

[bigdog9191999]

first off i would say that your results are in the normal range.

it will take a little for it to come back around to normal after having run it as it needs to "flush" it all back out.


on average if your not saving over 20% then it is just not worth the hassle unless your using it for performance, and most stock vehicles just dont NEED it, or can make best use of it.


here is the skinny on it. on the average driven vehicle it is usually just not worth it. dont mean it is better/worse just not mathematically worth it. the benefit is high performance stuff that takes premium or above, and the results are almost magical in a boosted vehicle ( that has been tuned correctly) as most vehicles that are boosted require premium or greater, and e85 is like running a mix of race gas and alcohol (because it is a form of it) the cooling properties of alcohol are awesome and to a point you can add more boost by simply adding more fuel. which means more power. and when prem is 1/3 more than reg and race fuel 5-7$ a gallon running e85 is dirt cheap and street legal. it just requires more of it, 20% in a stock type setup and up to about 40-50% more in a very high performance setup.

 

[CaptainAmerica1]

And E85 is just so much fun!!