token7888

The time has come to get new tires, but I am confused about what size came orginally on the Runner.

I have a 1992 3.slow Auto 4wd 4Runner SR5 with the factory alloy rims in 15x7.
The spare tire (which is dated 1992) is 31x10.5, but the door frame plate says 225x75. Which is the tire size that came on the truck from the factory?

The diameter difference is almost 3in!
How do i determine what axle ratio i have, and what size tire would work best with it?

Since most of my driving is local and on the road I am thinking about getting the Michelin LTX M/S for a little better ride and hopefully more mpg. Anyone use these tires before?
I am currently getting 13mpg on 31x10.5 AT tires

Any tips?

Thanks
J

jfreisner

33's were the stock size

kylextrisler

31's he means ;-)

GV27

LOL - I thought they were 35s......

Seriously though - I was thinking the 31x10.5s came with the SR5 package. Not sure about that, though.......

Do this: get out on the highway and set your cruise control to 60mph. Bring a stop watch with you or at least a watch with a second hand. Watch for a mile marker to come up and time yourself to the next one. It should take you pretty close to exactly one minute (give or take a couple of seconds) to get to the next. If you get there any slower than that (due to tread wear) or only slightly faster they you're on the right tires. If you get there significantly faster then you're currently on bigger that stock tires.

13mpg is lousy even for an auto geared for smaller tires though. You may have another issue.

Chris

MMA_Alex

check axle code against the list of axle codes. I cant remember what the stock gearing was for different tire sizes with the auto, but you can do a search and findout. that'll tell ya what size tires it came with.

Djlarroc

31x10.50x15

GV27

FWIW I just went out and checked mine and my door plate says 225x75 but mine most definitely came stock w/ 31x10.5s.

Belize Off Road Team

31"x10.5" 15R was an option, not standard on all SR5
you can go up to 33"x12.5" if wanted.

token7888

Thanks for the replies. I'll do the mile marker check after i find some markers around here. They are not as common here as in CA.

Part of the reason I only get 13mpg at best is because my commute involves alot of local driving below 25mph with lots of lights and sometimes being stuck behind the slow moving surface rail.
Last time I checked I get about 16mpg with mostly freeway driving.

I think I will stick with the 31x10.5's, else she'll be turning over 3k rpm at 60mph if I go down to the smaller tires. That will feel like a Miata...ha ha.

Thanks again,
J