Engine/Transmission (1994 - 1998) Need Better Mileage

[Buck88]

With the addition of the 370's, my mileage around town is in the 12mpg range :{ . My tires are 245/75/16, and I have 4:10 gears. I was thinking if I went to 285/75/16, and re-geared to 3:55's my mileage would increase. My question is... how much will this help my MPG's? Is something else wrong? no fuel leaks, checked that already. . Oh yeah, the HX40 isn't on the truck just yet, sitting in the garage, will the bigger turbo help?

 

[Timebomb]

I noticed mine has been down as well. I drive mainly interstate to work and some round town. Im in the high 14s low 15s. I dont get it. Ive got timing at 16deg new lift pump,filter,overflow valve,and 370s only have about 2000miles on them. Im not a heavy footed driver either.

 

[DieselDoghouse]

I can't speak for the regearing, but years ago I went from 245 to 285's on ARC rims. I think the combination of increased effective dia. and lighter rotational mass increased my mpg by 1. 0 or so. RPM's dropped as well.

 

[The patriot]

Could it be your fuel? Low/no sulphur, winter blend?

 

[RDelissen]

it's the combo of the smallish tires with the 4. 10 gears

I've got 265s on mine and get 12-13 towing and about 15-16 empty, but even though I could get better mileage by going with larger tires I wouldn't want to give up the 'towing-torque' I've currently got :-laf

 

[Signal73]

370's are mileage killers. On the highway I went from an honest 21 mpg down to 17 by switching injectors alone. Extroude hone injectors help that out a little if you keep your foot out of it. .

 

[Buck88]

oh well... looks like bigger tires, then maybe a re-gear. I've GOT to get better mileage! Thanks guys, Buck

 

[AWray]

Buck - Do some tuning with the AFC and fuel plate. Once all of the stuff in my sig was added, I got 13-14mpg on 285/75/16 BFG AT's. In the 20-25k miles since, I have improved the fuel mileage to 16. 8 mpg on the same tires.



I have corrected for the difference between the stock 245 tires and the current 285 tires. In 10k miles, there is only about 1 mpg difference between the corrected and uncorrected number.

 

[Ahopper]

my milage is just as bad if not worst and im ruinng my stock 180 injectors!! not that i drive the slowest in town but i still cant stand how bad im getting!!! only way for me to some what controll it is i need a block under my right foot!! :-laf but if im on the highway i can pull almost 20 sometimes repeat somtimes!!! :-laf

ps i forgot my gears are 3. 54's and im running 295/75/16 at full pressure

 

[Buck88]

What adjustments? Truck gets same mileage as it did stock! Well at least I think so... I can't keep my foot out of it right now, just got trans built, PDR HX40 on, and 370's. I know that I need to do some tuning. Right now as is, I can BLACK OUT the road!