I currently have 38x15.5r15 tires on my 94 chevy 1500. now my MPG isnt that good im getting about 300-320 per tank. Now im thinking if i go down to a 33x15.50r15 tire ill get better MPG? what do you guys think? im also wanting to know the best wearing MT tires you can buy? i was thinking the MT bear claws? any help fellas!!!  

a gear swap will probably cost the same as the new rubber. goto a 5:38 gear and the mileage will go up to nearly what it would get with 31" tires. I've never seen a baja claw with over 20,000 miles that wasn't bald. I got 36,000 out of a set of goodyear m/t's on the jeep  and have a set of toyo m/t's on a burb with 23,000 that should make it up to 28 or 30 if I'm lucky.

gees.....12mpg? my jeep doesn't even get that kind of mpg's! and your running 38's and a v-8.  

Now is that just changing the rear diff gears? now will thet affect when its in 4wd? what about highway with them gears????? this truck is my DD.  

both front and rear will have to be swaped..@65 it will only run at 2150 rpm, the 5:38 will improve the power and the mileage and have nearly the same spunk it had on the stock tires and gears.  

yep just ring and pinion gears......  

if you are aware of the gearing it has now I can figure the stock rpm to the needed gearing for comparison. O and the tranny, I'm assuming it's automatic, which makes little difference unless it is only a three speed auto someone swaped in.  

mudb8-.:
a gear swap will probably cost the same as the new rubber. goto a 5:38 gear and the mileage will go up to nearly what it would get with 31" tires. I've never seen a baja claw with over 20,000 miles that wasn't bald. I got 36,000 out of a set of goodyear m/t's on the jeep  and have a set of toyo m/t's on a burb with 23,000 that should make it up to 28 or 30 if I'm lucky.

gees.....12mpg? my jeep doesn't even get that kind of mpg's! and your running 38's and a v-8.

Gear swap will help get engine into a more efficient RPM range cruising but to suggest that you can get as good of MPG with 38's as you can with 31's is foolish. 38's have a LOT more rolling resistance and drag and then there is the aero dynamic drag of tires and truck sitting higher in air (trucks do not operate in a vacuum). All of this takes more power and fuel to overcome. If MPG is a serious concern, I would limit the look to 33's and stick with a fairly smooth tread and run decent air pressure in tires too. Good MPG and high lift with big tires do not go hand in hand here.  

snomans right if u really want good mpg then u would have to go down to 33 like i get 17 in town on my 2000 chevy 2500 gas engine so i dont got the best but also not the worst and im running 35" a/t bfg so maybe u could try 35" not althat way down from a 38  

that was "nearly as good" there I suggested......he is already getting close to 12 with the 38's he may get around 14 or so with the gear swap. wich is what most people are used to for a truck of that vintage depending on how they drive.

that thing would look pretty stupid running on a 8" lift and 33" or even 35" tires. the thing to do there is get rid of it and get another one.  

mudb8-.:
that was "nearly as good" there I suggested......he is already getting close to 12 with the 38's he may get around 14 or so with the gear swap. wich is what most people are used to for a truck of that vintage depending on how they drive.

that thing would look pretty stupid running on a 8" lift and 33" or even 35" tires. the thing to do there is get rid of it and get another one.

If he is really getting 12 MPG with 38's he is really lucky. 14 MPG even with a swap is a bit wishful in thinking (maybe at 60 MPH or so and a tail winds too) Even a downsize to some smooth treaded 35's would reduce drag and increase MPG.  Extra drag from lift and tires can eat into MPG a lot at times.  

yep, I agree with that! he said 320 miles to a tank.......
I figured about 28 gallons, just guessing.....ok the guess was off, It's 11.42  

the one I had got 14-16 driving like a sane person with 38.5's and that was with 4:10's, 38.5's and a 350 tbi with a th 400 tranny. I put a crane 260 roller cam in it also.  

I recently took a small trip in my 2000 K3500. It was 10 out and a bit windy and truck has 4 studded 10 ply rated bias plied truck type aggressive mud/snows on 16.5 rims. It does not roll well with them on and with about 800 lbs of salt bags in bed and a rear mounted spreader in hitch I got close to 15 MPG running about 65 or a bit less with a bit of town driving too. (never exceeded 67 according to GPS) I consider this great MPG for its current configuration. I have seen a lot of wild claims for MPG out there but I take a lot of them with a grain of salt because some are far fetched.  

some skinny load range e tires at 37" less rolling resistance,smoove tread and higher psi in tires,that work ,maybe? figure less contact patch on ground with harder rubber and mild tread would  help,just my observation, but now with smaller tire 33-35.12.50 would he get bettr articulation for better off roading?  

Thanx for the info, changing gears and such isnt what i want to do. I really need to sell the truck. Anyone interested?