Another gas mileage thread...done just about everything and still ~15-17mpg

the truck: 1995.5 V6 SR5 4x4 with auto tranny. the truck has ~123k miles on it (all original). i got it when it had 88k and in the time i've owned it i've done all the maintenance. when i first got the truck it would get 17-18mpg on average, now its a little lower like 15-17mpg.

in the last year i've added new OEM parts:

-fuel filter
-o2 sensor (front)
-plug wires

the mods are:

-K&N intake with heat shield
-3" susp. lift
-265/75-16 BFG AT's

also in the last year i've changed all the fluids (tranny, f. diff, r. diff, t. case) and it has fresh synthetic oil. i seafoamed the engine at the last oil change and got a decent amount of smoke out. i'm still trying to figure out what else i can do to get better gas mileage. i hear about guys getting upwards of 20mpg and i'm frustrated because i'm averaging less.

*on a side note, on ONE trip i got 24 mpg coming back from denver (to albuquerque), following my mom who was towing a trailer going 60mph!


SOOOO, what do you guys think i can do? i don't drive crazy around town...i pretty much drive my truck like an old man...my WRX on the other hand i drive like a dumb teen with a wild hair up his arse. i've heard about people cleaning the maf sensor, would that help? what if i reinstalled my stock intake piping with drop-in K&N filter and deckplate mod? would that increase mpg's? also i may need new spark plugs, what would you recommend?

thanks!

 

that about what my 98 w/110k, ive heard of plenty of people getting 20-24

 

thats a lot of tire to get rolling dude. thats a definite decrease in mileage right there.

 

you think? its ~.5" taller than stock...pretty close to a 31" tire. the tires i had before were 265/70-16...so i barely went up in size. i could see if i got some 285 or 305's...but going from a 70 to 75 sidewall shouldn't cause that much difference in gas mileage

 

yeah....that tire size alone shouldnt make barely any difference in a mileage change, even tho the bfg's are a heavier tire than most, it shouldnt make that big of a difference.

 

true...i went with the load range D which is still heavier than most. the load range E is even worse! that would contribute to additional rotational mass which would decrease the mileage...

 

YES - change the spark plugs. Get OEM /pregapped.

Have you run any fuel injector cleaner through the system?

Take the intake off and put the stock box back on and see if anything changes.

What was the mileage before the lift/tires VS after the lift & tires?

When did this drastic change in MPG change? What was the latest upgrade?

 

no, but i'm planning on doing it within the next 5k miles or so. i'm going to change the belt, pulleys, water pump, tensioner, and my valve cover gaskets cuz they leak a little, lol. anyhow, i seriously doubt that it would stretch and cause poor performance...but you never know!

 

mine is about the same 16-18 same tires same lift but when i got it had 225/70r16 tires and it did 23mpg what gears do you have i think mine has 3.55s with auto but it costs 1500-1800for parts and labor