9 MPG… help

[Mikemarti02]

Hi guys, I have a 1995 gmc k1500. It’s got 33s with aluminum rims, and I get 9mpg. Best I ever got was 13 on the highway and that was once. Usually around 11 combined. I will get an engine light if I run it more than 20 mins, but it self erases every time and I cannot read it. It has a little stumble here and there. Anyone have any ideas on what it could be?

 

[fancyTBI]

From that information alone it would be impossible to properly diagnose.

What engine/trans? When’s the last time you did a regular tune up? How old is your O2 sensor? If your CEL comes on, you’ve got a stored code. Can you even read it by jumping the pins on the ALDL port?

How long have you owned it? Has it been getting worse lately or has it always gotten 9mpg?

 

[Sean Buick 76]

Have a shop hookup a scanner and monitor it while it’s being driven.

 

[Caman96]

What mpg are you expecting? Getting stock sized tires, a tune-up, fresh o2 sensors you might gain 3 mpg(getting 12 mpg)which seems pretty common from many on forum. 13-17 is what mine got new.

 

[1998_K1500_Sub]

Hi guys, I have a 1995 gmc k1500. It’s got 33s with aluminum rims, and I get 9mpg.

How are you calculating MPG, using the odometer mileage or other?

If odometer, did you make changes so it reads correctly with the bigger tires?

Too, an aggressive tire tread may cost you MPG.

 

[Hipster]

Lots not mentioned , cranked/alignment correction? dragging brakes/wheel bearings? aggressive tread patterns. driving style/hammering it leaving stop lights/ forcing downshifts every time you accelerate, and the list goes on and on.

 

[Caman96]

…another might just be it’s a 29 year old truck.

 

[termite]

If its any consolation OP, I average 6mpg in my suburban. And don't expect much better from it.

As others have said, tune-up, check alignment, check brakes, deal with the CEL light and ride on to the next gas pump.

 

[99xcss4]

when ever I get it going I know for a fact that the frank'n truck will pas every thing but a gas station

 

[Hipster]

when ever I get it going I know for a fact that the frank'n truck will pas every thing but a gas station

Words to live by lol.