Ppat,

I wouldn't recommend staggering sizes on an AWD car. It adds to the workload on the center differential and just increases the already overwhelming understeer. Some folks use 235 width tires all around but your safest bet is a 225 width tire on a 7.5" wheel.

 

Few months back I posted a very extensive post about this. Try to find it.

I am running 245/40/17 all around o 17x8.5 rims.

My pal is running 255/40/17 all around on 17x8.5 rims.

There are many factors that will determine how wide you can go.

 

Changing the width will not matter to the AWD system, as long as both front and rear wheels have equal rolling diameter. Your overall rolling diamtere will affect your speedometer reading.

 

The only benefit will be cosmetic. You'll likely have to do fender work and you will only be increasing the sensation of the already crippling understeer - which will keep your cornering performance the exact same even if you go with 315s in the rear.

 

As long as you keep the same overall rolling diameter.

The funny thing is, on Impreza's, wider rims fit in the front. Lots of JDM tuners use 8.5 in the rear and 9 in the front with SAME tire.

The thing is, your front/rear wheels will never have identical rolling diameter. Tires wear out differently. So, in reality "it is ok" to have NOT IDENTICAL front and rear. It is a matter how different they are. What will happe, is that once the difference becomes more than 0mm, the center diff will be "overworking". The tranny fluid will heat up, the diff will heat up. At some point, when the difference is too great, the diff will expload. How much difference is ok, I do not know.

I am going to try to run

17x8.5 with 255/40/17 in the rear
17x7 with 225/45/17 in the front

Above setup has nearly identical overall rolling diameter but ~30mm width difference.

CUSCO Tarmac Gear 35/65 center diff w/ CUSCO RS rear diff with STi Suretrack diff in the front. Such setup, based on my calculations and discussions with various people will give me a tail happy WRX with oversteer saving front. Should be pretty fun.

The overall diameter is nearly identical but such setup will provide me with better steering response and turn in/out.

Right now I am using 245/40/17 all around like I said, and the car is pretty hard to turn. Not hard to complain, but harder than before when I ran 225/45/17 all around.

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What I said above is pretty complicated and for most people, I strongly recommend running no wider than 235 tires ALL AROUND with same width and diam rims and no less than +45 offset.

- Alex

 

So would 8.5 be to big for a stock hight WRX??? Imprezer what was the tread called that you had going on a while ago??? can you give me any tips on finding it please.

 

https://www.i-club.com/forums/showth...ight=coilovers

Here is another good one

https://www.i-club.com/forums/showth...ight=coilovers