[2dor4x4]

Im just wondering about what kinda gas mile i should be getting. I just got this truck its a extended cab 1998 gmc z71 k1500 with the 14 bolt. and im averaging like 10 to 11 likes to the gallon. 5.8 gallons get me about 45-60 miles depend on driving style. the only thing different from stock is that it has 285 ATs on it. And i just put new fuel filter, spark plug, and wires.

 

[2dor4x4]

Anyone?

 

[DirtyBlackHoe]

what gears are in the 14 bolt...when i had that same truck with 33x12.50 on 15x10's I averaged close to 14-15 in town and 16-17 on highway

 

[2dor4x4]

I have no idea what gears are in it. Someone told me sense it has the 14 bolt it have a a 4l80e trans. But i wish i could get 14

 

[Spence]

Gas mileage is VERY much dependent upon driving style.

 

[2dor4x4]

Yeah but i drive easy, the rpm gauge dosnt go over 2grand.

 

[04_GREEN_Z71]

Was it reprogrammed for larger tires?

 

[09WhiteHD]

if your speedo was not recaliberated it would throw your numbers off pretty far.

 

[00z71lt]

yea you can't forget to correct your mileage math for the difference in tire size. Honestly you probably won't get better than 12-14 in real world conditions. My 1993 and 1995 although 2500s didn't get over 12mpgs. You may have the light duty 2500 with the 14 bolt semi float axle and 6lug wheels.

 

[Silverado_06]

15ish. depends on driving style. stock the best i could do was 18.

 

[Hunter.]

15-17

 

[Evan]

You don't have the 4l80e in a half ton unless someone else put it in there. And I doubt they did.

 

[JimmyBeam]

Gas mileage is VERY much dependent upon driving style.

+1 Absolutely

I range from 13-14 all the way to 16-17 depending on how heavy my foot is

 

[scarber08]

Our 94 ext cab Z71 silverado gets 15-16mpg with the 350 and (I'm pretty sure) 3.73s.

 

[Tiki]

Should be able to pull 15-16 if you granny it :imo Sea Foam, plugs, tune, etc. and it will come back to life :imo

 

[2dor4x4]

I did put plugs wires and i ran some sea foam and still shitty

 

[5spd Z71]

my 95 usually gets between 14-high15's around town, with the 5.7 and 3.43 gears.

 

[furnace mstr]

check your o2 sensors?

 

[2dor4x4]

It dosnt throw a check engine light

 

[Tdaz250]

Was it reprogrammed for larger tires?

This