i recently went from 265 bfg rugged trails, to 285 bfg at's.. now i hate my truck, i lost like 2-3 mpg's.. given the old tires were small and bald and the 285's look good but i commute alot and up huge grades. ive lost all my power, i dont tow and im leaning towards 4.10's. but those of you who have regeared with the 4.6 what kinda mileage difference did you get back? was it worth it? ------97 scab 4x4. SPANKS GUYS!!!

 

what gears do you have now???

 

you may not have lost that much mileage if you didn't adjust your speedometer...because your actually going further than your truck says you are

 

Lost all power and 2-3mpg from a 265 up to a 285? 285 what...75r17? so a 32.7x11.5x17 or what not. I wouldn't think they would make that big of a difference, noticeable maybe but not that bad. Maybe your due for a good tune up Not that gears wouldn't help, they obviously would but if going to a 285 made you lose that much power and mileage then I would look into a good tuneup and cleaning.

 

Bingo!

Gears will really help with getting the truck moving good again. If you have 3.55 then I'd go with 4.10. It's gonna cost anywhere from $1,000 to $1,500 installed for a 4x4. I would also look into getting a tune to recalibrate your speedometer and get some power back.

 

yup you need to change out your speedo gear and then a programmer first to change your shift points before you spend 1500 plus on gears would be best imo.

 

Ah good point, just noticed he has a 97'.

 

sorry guys thanks for the responses though... so explain to me how to figure my mileage diference??? i understand what your sayin but cant figure out the math. also where can i get the gear for the speedo?? and i dont think i can change my shift points can i?? its a 97 but has a 98 trans in it. Stock gears, im assuming 3.55 but may be 3.73 since i have the tow package and extra trans and P/S coolers and stuff. I went from 265/75/16 to 285/75/16. Coming up hills before i could just fly up the hills with OD off and now im back and fourth between 2nd and 3rd, OD is not an option. ill most likely be doin the gears myself but i figure if i get some mileage back with power i might be more satisfied and less disgusted.

 

what's the axle code??? sounds like you have 3.03 or 3.55 gears in it now

 

what kind of mileage were you getting with the 265s?

 

As of now I don't know the axle code but I think it was "H"? With the 265's I was getting a constant 14-15 maybe higher on flatter ground my guess around 17-18 max highway mpg. Now I'm down to 11-12 under regular driving not slow but not haulin ***. I can nurse 13-14 if I keep it under 55 mph though.

 

code H what??? H9 is 3.55 limited slip

 

trust me you would know if you had 3.08's you would have no ***** NONE you have to double down shift on the highway just to pass and you have to downshift to speed up ... lol then try that with 37's ... just one more week ...

as for ****ty power and such change out the speedo gear on this year truck it effects the shift points as well as other components but i know when i did mine it totally changed the way my truck drove ....