Hey guys, I've spent the last half hour on here searching, but to no avail. I have a '94 4runner with a 22re and a 5 speed, and am currently running 235 75 15 . I hate the way it looks with puny tires like these on it, so I am thinking that I may go to 31x 10.5 or 30x9.5 tires to fill the wheel well better. My first question is will going to larger tires like these change my speedometer reading? And I am also trying to not affect my gas mileage too much either, so I am wondering if anybody has any idea how much mileage I would lose by having an extra 2.5 inches of tire width. Im thinking of running an all terrain tire so nothing too noisy or aggressive. I get 24 mpg with my current balding 235 75 15, which is pretty good, so hopefully with the right choice of tire, I won't lose too much. Most of my driving is 75% city/highway driving and 25% wheeling. Thanks guys!

 

with 31s you might get 20mpg and it wont throw the speedo off by much

 

My 31's throw me off by maybe 2mph at 55mph...but I know the percentage of that goes down in lower speeds. So in actuality, I do 52-53 in a 55. The higher speed...well it really doesn't see over 65mph...but I compensate for it more greater at higher speeds.

 

Thanks man, I'm thinking that 30x9.5 might spare 3/4 to a mile per gallon and not look much different than 31s. The more I think about the gas mileage, the more I'm tempted to go with 235 again. It looks kind of wimpy with bald tires and the stock steel wheels. I'll be ordering the 3rd gen 15
x7 aluminum rims this week off ebay, so that will make a big appearance upgrade.

 

its not bad, my 31s on my 89 get like 17-18 city w/ harshish driving, but i just put them on a few days ago, but the previous 31s were street tread and ...

 

I spoke with Brian of wabfab and he had some 30x9.50x15 tires he said he had sitting around still in great shape. Might wanna shoot him an email through his website and ask if he still has them because you might be able to get them cheaper through him instead of getting new ones.

 

Do you have any idea what brand? I'm considering some kind of all terrain type. Thanks for the heads up!

 

Not sure....shoot him an email...

 

you stated that you have a 235/75 now?

If you buy a 30x 950, you will be at nearly the same width, and a 31x10.50 is only an inch wider, FWIW.

the 30's will not appear much bigger than what you have, although an agressive tread pattern will give you a better look, and add apparent size.

 

http://www.off-road.com/toyota/proje...ro-to-gearing/

http://www.4lo.com/4LoCalc.htm


There you go

 

I've always heard that by using taller tires you get an increase in milage but I've never been able to clock it because I haven't corrected my speedometer. The key is that you have to check your milage with a known distance or get your speedometer corrected to be able to tell.

If you go with a slightly taller tire, and a slightly wider tire, it's very well possible that you may see the same milage.

 

Larger tires are also heavier. Weight, any kind of weight, is the enemy of fuel mileage. So not only are bigger tires heavier, they increase the rotating weight. That means you have to get them up to speed every time you accelerate. Taller tires also put the vehicle up in the air higher. That's great for clearance underneath, but also causes more drag when driving down the road. You can likely see decreased fuel mileage with larger tires, even with the taller 'actual' gearing (that the engine sees). When on-road, keep your tires properly inflated. That's the best way to help your mileage figure.

Mike in AR

 

100% agreed

 

"I hate the way it looks with puny tires"

I understand. Personally, I think it is worth it to have something I enjoy looking at and driving, even if you lose a little gas mileage, which will not be much. I vote for the 31x10.50.

 

When I got my 4 Runner, it had the same size tires that your's has now. I switched to 31x10.5x15 BFG All terrains. The guys at the tire shop said it would throw my speedo/odometer off by about 10%. FWIW a few weeks ago I went on a trip with my mom and we compared the mileage on her stock jeep liberty to mine with the bigger tires, and it seemed to work out to about 12-13% difference (assuming her speedo/odo is correct). I haven't noticed a signifigant difference in my gas mileage, not anything to cry about anyway, and i drive about 100kms a day to work & back. It takes a little longer to get her up to speed, once you get going though its fine. IMO its worth the small sacrifices in power/gas mileage on the road to have the bigger tires for off road, and they do look soooo much better.

 

I believe from a 225/75/15, stock for my 87, to a 31/10.5/15, what I have now, it changes the speedometer by about 8.5%

 

my 235's are shot and i'll move up to the 30x9.5's for the looks. wanted the 31's (265) but decided against for weight reasons, chance of loosing too much acceleration for my taste.

 

Weight reasons? How much more do you think a 30" weighs as opposed to a 31"? Please do not take this bad, but that is like saying one should not eat before driving because they will raise the weight of the vehicle. I agree that bigger tires are heavier than smaller. But 1"? That is only going to be a few pounds tops.

 

A one-inch taller tire gains you 1/2 inch extra ground clearace. And, that's OK. The good news about a taller tire is that it is just over 3 inches longer around. That makes for a longer tread footprint on the road. I went with the 31's just for that reason. Seems to help with directional stability - especially in in less than ideal situations like: rain, snow, loose, etc.

Mike in AR

 

true. stock on mine was a 225, weight around 26# (using Dayton weights on the Bridgestone site). i'm running 235s now, 30# each. frankly, acceleration is OK, isn't fantastic, not that the 22re is a burner to begin with. but a difference between these two sizes can be felt.
going to 30x9.5 increases weight to 36#, the 31x10.5 is 40#, granted not appreciably greater.
if i can tell the difference in the 235's over stock, and the 30s increase the weight by 10#/tire over stock, i'm going to notice it. i'm talking a DD here. if it were strickly off-road, 31's for sure. but i'm not. an extra 1" ain't worth it for me, and pushing the 22re even further will make my winter pull up the pass even more frustrating.
that's why most on this site run two sets of rubber.
there was a good thread not too long about mpg and tire sizes. i'll see if i can find it.