I am going to go to a smaller tire size on my jeep to help with MPG. I'm currently running 31-10-50's and I want to buy 4 tires that area On Road/Off Road that are all season and will help me get better MPG. My Jeep is only getting 8-11 MPG, I'm hoping to get in the upper teens or 20 on MPG. If it's even possible. I have a buddy that swears he's getting 18 around town and 20+ on a trip if he drives the speed limit or near it. Any suggestions on tires or MPG advice??? What say you???

goodyear wrangler all season.

What size would you suggest???

no lift? 30's or stock size

I have no lift and a buddy went from 31-10-50's to a smaller size and he said he gets about 2 more MPG? How many MPG do you get?

No offense but you are being overly optimistic if you think changing tires will double your mileage. I have the 2.5 with auto and 275's on it and I am getting in the mid to upper teens. Sounds like it isn't your tires. Could be alot of things from worn out engine to O2 sensor to Cat converter to tune up to the way you drive. I would look at all that before changing tires that way you will know if you really made a difference before you changed the tires.

No joke.... how the hell do you only get 8-11 mpg, I get at least 20 mpg in my 4.0,2in lift and 33's,I just drive really smart(no high RPM's or flooring it)

Well I hear ya but my motor is solid and runs great. I do not have any check engine lights on so I wouldn't think I have any sensors down and my Jeep currently does not have a Cat. My Jeep is also a standard shift and from the factory the Standadr shifts get about 3-4 better MPG than the auto. Tire size should help, not double though. I am just wanting to get up in the upper teens and as close to 20 or better if possible. I'm currently get between 8-11 and it should do much much better than that, ya know?

How the hell do I know, I drive it right and never hot rod my Jeep and it just loves the Petrol. Go figure???

Not to insult, but how are you figuring
you gas milage?

Well pretty simple or atleast I thought it was. I fill the tank to the max amount (running out on ground full) I then proceed to drive about a 100 miles or so and then I re-fill agian the same way. I take the total gallons needed to fill it back up and divide it by he miles actually driven. Gives a pretty good guess but it is not exact. This is another way to look at it. I live 30 miles from work so there and back is about 60 miles. I usually go about 10 miles a day going to lunch and running, so that is a total of 70 miles. It's costing me between 17-20 bucks a day in gas. Now thats actually green out of my pocket, no formulas or specualtion. At 2.69 per gallon the math is pretty simple, that is why I'm so anxious to increase my mileage.

i just dont see how its so bad on gas??? My jeep even with the stuff i have done gets better or just as good MPG as my GF's Olds Alero, go figure haha

Hey jeepz could you post a pic or pm me a pic of your jeep. I have been looking at those wheels and was wondering what they look like thank you

Do not forget where you live makes a difference Ohio is pretty flat not much hills. I live in northern vermont, It is pretty much all mountains. I run a 2.5 with 33's and I get about 12.5 mpg.
Do not take this the wrong way but if you are worried about fuel mileage maybe you should pick up a cheap car that get's 25-30 mpg and park your jeep during the week. At that gain of saving fuel it would pay for itself.
Jeeps were not made to get great mileage.

I'm looking for a tire size and kind???

I had someone swear by Michelin LTX tires on his truck, and I tried them out myself on my Jeep (I'm actually on my second full set). They provide adequate traction for mild off-roadng and are a lot quieter/smoother than the original Wrangler tires on road. I also get decent gas mileage--high teens city to 21 mpg hwy ('97 four banger). I've got stock size tires (I've wanted to go bigger for a while, but with limited funds, other Jeep repairs, and not too much time to go offroading recently, I figure my current tires and mpg probably serve me best at the moment). So, the Michelin LTXs will be really good for you on-road, and they shouldn't slow you down off road provided you're not doing serious offroading. Also, in case it matters to your decision, my last set lasted me around 65,000-68,000 miles.

Just a quick note on this....Tire size generally doesnt really equal more real miles per gallon. In actuality, changing from the stock tire size WILL change the accuracy of your speedometer. Since the tripometer is what you use to figure out the mpg, and the speedometer controls the tripometer, the mpg isnt really accurate with tires larger than stock. BUT, by changing tire size, you are changing the speedo accuracy, and by going down in size it will calculate as though your mpg is better.

Most people forget this when changing their tire size. Some tread patterns and lighter wheel tire combos will help with fuel cost, but the cost savings probably wont be significant enough to offset the cost of new tires - unless you were going to buy them anyway.

I hated the GY Wranglers that came stock on my 94. First real offroad trip resulted in a sidewall blowout. Immediately afterwards replaced them with the BFG 30x9.5 AT, and am now on the second set. The new ones are BFG AT KO 30x9.5. Mileage is still 15-20 in mixed driving, the size requires no mods to fit. I only rub the springs a hair at full turn (Can be avoided by adjusting the lock, but why bother?). I selected the BFGs because of the extra ply in the sidewall. The blowout happened on the PA turnpike at 70MPH after a trip down in Shanandoah. The hole that exploded out of the sidewall was the size of a baseball and likely resulted from rubbing the deflated sidewall against a rock while on the trail. I should have spent more time inspecting the tires when airing back up, and have since adopted a more comprehensive inspection after every offroad trip. Still, an offroad tire should be able to take a lot of abuse, and the GYs failed. The BFG ATs are a compromise tire, as the tread isn't as aggressive as the MTs, and the noise isn't too bad. They can get clogged with the sticky mud or packed snow, but that can happen with almost any tire. You can usually get these for just over $100 each, so replacing all 5 costs about $550. by the time you get them mounted, balanced, valve stems, and whatnot. Don't forget to replace the spare!!! I had to mod the mount and the third eye light to fit the larger tire on mine, but is was relatively simple to make an adapter plate to raise the mount (Had to clear the rear bumper - also custom) and to insert a spacer at the base of the third eye mount.

I think I might just to Wally world and get me four Good Year Wranglers 30x9. That should lower the jeep just a har and they weigh a few pounds less on each tire than the 31x10's I'm currently running. They have a great warranty also.

Last time I checked my mpg I was getting 17.2 mpg. That was about 130.1 miles on 7.56 gallons of gas. Noticed my gauge is a little funny seems to drop slowly above 1/2 tank then seems to drop more rapidly beyond that. I don't have a lift as of yet. I am running Goodyear Duratrac tires size LT235/75R15. Pretty close to a 30x9.5R15. I'm pretty happy with 17 mpg. I might even be able to squeeze out more with shifting with the light. I might need a new o2 sensor. Unless I got the wires wet when I degreased my engine but I flashed a code 21.

I was thinking that a 235 would be much smaller than a 30x9. I was thinking that was more along the lines of say a 265 tire.

I have a '91 w/worn out 2.5 (176K) 31x10.5 mudders and I get 15 mpg. I am also not running a cat and drive it pretty hard. I used to have 32x11.5 tires and didn't notice much deifference in mpg when I went down in size. I think something else is wrong and am afraid that you might be disappointed with the change in tires.

235/75r15 is about 28.9" tire a 30x9.5 is about a 29.5" tire. only about a .5" difference on height.

thats a goodyear tire might be slighty different on a different brand

Well that is very interesting. I how ever would have thought that the 265 would be more closer to that size but I guess thats what I get for thinking. LOL

In theory, a taller tire should be MORE fuel efficient, especially for highway miles. Think gears, with your tire being the final gear. The taller your final gear, the fewer the RPMs to turn it. This is a big factor in bicycles, especially in the days before chains when they made the wheel HUGE.

More practically, you just need less rolling resistance, and that will make a much bigger difference than height. So a tall skinny tire with pure highway tread, with very high pressure and very little sidewall give. Which is pretty much what Semi trucks use. It's also what they use on mileage champ cars. Remember that Geo Metro that got 50 plus MPG? Relatively tall skinny tires with 50 pounds of pressure. Almost bike like.

And the exact opposite of most most people want in a Jeep tire.

might also want to consider weight.
took out the rear seat, radio, and spare tire and I "think" I improve my mpg.
thinking about removing the A/C and have an electric fan.

I have 31 michelins on 15x8 rims and when they need replacing I will go back to a stock size on 15x7 or if I find a nice set of 16x7 5x4.5 .....

You aren't going to see any mpg change from a 31" tire to a 30".... I got 17mpg on 37's and a 4cyl. Its how you drive and the gears you run.

Try putting your Cat back on. That might be the problem. My Cat went bad and when I replaced it my mpg increased, go figure.

when I got my 95 ,2.5 5speed.31 10.50. It had only a cat and muffler .Ran like shit .Couldnt get outof its own way.In 15 miles drank up 10bucks in gas,put the factory tail pipe on and whamo fixed it right up.PUT the Cat back on, the comp.is metered for it to be there . when you remove things it will screw up back pressure and the comp. may change the air /fuel mixtures hench bad milage and performance.tire size is not going to make a differance.That my 2 cents

I believe the Cat is off mine.