Hey guys and gals,
I just got my 1G back from my in laws after they stored it while I was in the military. While stationed in Japan I got some 18x8 and 18x9 rims for free. They both are +37 offset. My question is what size tire do I use to make them work on my first gen. A's of right now they are 225/40r18 on the x8 and 265/35 18 on the x9. The tires need to be replaced and wondering what size tires to get? I mounted them and they cleared...the rear just barely.

Here are some pictures to see what they look like, don't mind the nastiness that is my car it's been sitting for around 7 years and just starting to restore it.

You can run whatever tire size you want. You'll just need to take 2 primary things into consideration:

1) The rolling diameter of the tire from front to rear ABSOLUTELY needs to be nearly identical. Running a staggered wheel setup is fine, but if you have too much variation in the rolling diameter from front to rear, you'll cook the VC. You can check this by wrapping a string around the diameter of the tire, and measuring it. Do the front tires, and then compare that measurement to the rear. The more variation you have, the greater the chance you could possibly damage drivetrain components. I'm not aware of an exact spec, but I've read you want to be under 1/4" variation front to rear. Someone feel free to chime in if that's wrong, or if there's an actual spec put out by Mitsu. Regardless, the closer you are to the same, the better.

2) You'll just need to pick a tire that fits the car. That means a tire that allows the suspension to still have full travel (no rubbing) and clear other various components. Usually, people have issues clearing the front strut spring perch with an abnormally wide tire. You'll also need to verify clearance on the control arms and lower fender lips.

3) Lastly (this is my advice more than a requirement), running a tire with a narrow section width on a wide a$$ rim is stupid. If you have a 9" wide wheel, you damn well better be running a tire with a 9" section width or better. Don't be the guy stretching the sidewall out on a 205 series tire just so it fits a 9" wheel. If you do decided to do that, I would direct you to spend the majority of your time posting here: http://www.stancenation.com/tag/hellaflush/

Personally, I'd run widest 40-45 series tire I possibly could before I started having clearance issues. Those are good looking wheels IMO. Never seen them before. What brand are they?

Ive always been under the impression that running different size tires/wheels front and rear is really bad on the differentials in an AWD platform, even if the rolling diameter is close. Id like to see some more information on this, as I am curious.

kchaazz said:

Ive always been under the impression that running different size tires/wheels front and rear is really bad on the differentials in an AWD platform, even if the rolling diameter is close. Id like to see some more information on this, as I am curious.

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GST with PSI said:

You can run whatever tire size you want. You'll just need to take 2 primary things into consideration:
1) The rolling diameter of the tire from front to rear ABSOLUTELY needs to be nearly identical. Running a staggered wheel setup is fine, but if you have too much variation in the rolling diameter from front to rear, you'll cook the VC.

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The rolling diameter is what needs to be ^^ nearly identical.

Rolling diameter as stated above because that is the part that touches the ground. As long as it covers the same distance per revolution, you are fine.

You could just run 245/35/18 all around and be done with it. 245 is about the widest tire you can fit without rubbing the control arms. Stock height you can get away without rubbing the fenders too bad but once you lower you will rub with the 9" wheel, in which case look into rolling the rear fenders.

I say 245 size tire because the tire wont stretch as much on the 18x9 and on the 18x8 it will sit on the wheel just about perfect. Take it from someone whos been working with custom wheels for quite some time.

You're going to piss off you center diff running those tires.

Chumpaumpalumpa said:

Rolling diameter as stated above because that is the part that touches the ground. As long as it covers the same distance per revolution, you are fine.

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Exactly.

Ok so my plan is to run 225/40 up front and a 255/35 in the rear. The is a -0.24% difference. Or 0.06 of an inch as shown in the link http://www.1010tires.com/Tools/Tire-Size-Calculator/225-40R18/265-35R18/255-35R18
As for the rims they are SSR AGLE strusse from Japan when I was stationed there, bought the car they were on and decided to keep them. I like that they are different now just need to make em work.

0.18in difference, 78.81in-78.63in=0.18in

1slo1g said:

Ok so my plan is to run 225/40 up front and a 255/35 in the rear. The is a -0.24% difference. Or 0.06 of an inch as shown in the link http://www.1010tires.com/Tools/Tire-Size-Calculator/225-40R18/265-35R18/255-35R18
As for the rims they are SSR AGLE strusse from Japan when I was stationed there, bought the car they were on and decided to keep them. I like that they are different now just need to make em work.

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Can I ask why you would run a very different tire setup? That's a huge difference, potentially destroying drivetrain parts. Not to mention won't help you much traction wise with the 255's on the rear. Plus you're not going to rotate them so you're going to get much less mileage out of the tires.