12 mpg

From the looks of your signature you have already done just about everything that you could possibly do to decrease your gas mileage.

First dump the tires. IMO

Large tires usually kill your gas mileage. More meat to turn = lower gas mileage.

Sorry but that’s the way it works. The best tires for mileage would be what came on the truck new.

You've obviously made yourself a dirt thrower, so lower fuel MPG is going to result. But at least you'll have fun while you're sucking down the petrol. :great:

I agree with Fiero. The tires are killing you. Do you commute in this vehicle?

I dont see anything in there about changing the gears when you went to larger tires. A new set of gears could gain back some power and MPG.

Gears, gears, gears !
Depending on tire size / tranny.......
33's = 3.73 - 4.10
35's = 4.10 - 4.56
Bigger = lower

Coast and save

Changing driving style is the easiest way to get better mileage. A local news broadcast had a newsman drive a Ford Explorer and he got 15mpg. A "hypermiler" driver got 28mpg. He did this primarily with less aggressive driving and coasting to stoplights with the engine off and shutting off the engine at lights. See more about hypermilers.
You don't have to own a hybrid to get great gas mileage, you just have to be willing to change how you drive.:great:
Caution: Turning off your vehicle while driving is something that should be practiced......your steering can lock and that would be bad while moving.

Hey maybe you can get on those deal like the autobahn cars at Disneyland when you stop the engine shuts off when you give it gas the engine starts and away you go. I think they have the same setup on gas golf carts.

mpg with alternatives sparks

I´ve listened that a alternative sparks than platinium (acdelco or others) affect seriously the mpg. I don´t know why, but a couple of friends have a tahoe and suburban 1997 (i have a chevy silverado 1997 ) and ever said me that i must to look for the original sparks.

And, try to change to air intake stuff because if i change for a conic filter i will get a hp extra and if i drive at city between 1 k and 2 k (max 2.5) the consumption will decrease (mpg will grow up).

Thanks.

Have you adjusted for the increased tire diameter?

Have you adjusted your calculations for increased tire diameter.Your current tires are about 15% bigger than your old tires,so you are traveling about 15% father than your odometer says you traveled?
Like everyone said, wider tires with more aggressive lugs greatly increase rolling resistance,and kill mpg.Raising the truck usually increases aero drag and kills mpg.
CAI's can't increase part throttle FE in a modern spark ignition vehicle.More peak power, maybe, but not FE.It is really tough to improve on factory FE with any sort of add on mod.The factories do a very good job maxing FE.About all you can do is increase tire pressure(harsher ride usually),and change your driving habits.Pulse and glide-accel to about 4 mph above the limit,and lift off the gas gliding to about 5 mph less than the speed limit-repeat-try to stay off the brakes and the gas.
Luck,
Charlie