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[Black Gold]

Ok guys, i have noticed that there is a small problem in this specific forum. That problem is that a lot of people do not understand offsets and do not understand how to tell if a particular wheel will fit on their car because they dont understand offsets.

First off, i will base this on the 135 with sport package, and the wheels that come with this car.

The first thing you need to know is the offset AND WIDTH of your current wheels. For the 135, the OEM wheel specs are

Front - 18x7.5 ET49
Rear - 18x8.5 ET52

Typically this car, in stock form, cannot handle more than a 15mm spacer up front, and maybe a 12mm in the rear. Spacers affect the offset of the wheel by pushing it OUT farther. A lower number for offset means that the wheel is pushed out farther and is "more aggressive".

So if we use that as a guideline, the most aggressive you can get (unless we are talking about super lowered cars which changes things as there is not a lot of fender clearance on this car) is....(IMPORTANT to note that you can only compare ET offsets on wheels that are the same widths. Wider wheels with the same ET offsets are more aggressive)

Front - 18x7.5 ET34 (absolute max, possibly will still rub)
Rear - 18x8.5 ET40

So that is a really simple way to understand how a wheel with the same width but different offsets will fit on your car.

IF the new wheels have different widths, you can use this simple tool from 1010tires to calculate the effective difference in offset between your current wheels, and the new wheels.

http://www.1010tires.com/WheelOffsetCalculator.asp

What you want to notice is the "outer position" calculation. This will tell you how much the new wheels will "extend" relative to your current wheels. Since before we said that a 15mm increase in offset is about the max on the front, and 12mm is the max in the rear, you want to stick with a wheel that will stay at or lower than those numbers.

You can try to get away with a more aggressive offset by running stretched tires and other IMO half ass solutions, but this guide is a very simple way of understanding how to find wheels that fit PROPERLY on this car.

Good luck, hope this helps.

Feel free to ask any questions if you still arent quite certain of how this works.

[BrokenVert]

1010tire calculator is great - been using it for years


Let me change something quickly though. Your example 7.5 et 34 is a bit wrong.

I run 8inch et 40 wheels in the front which have the same position relative to the inner fender in front - and with a 225 it doesnt rub.

[Joaco135]

I run 18x8 et35 with 215/40 & 18x9 et40 with 245/35 lowerred on H&R springs without rolling the fenders and only rub slightly on big dips at fast speeds but for the must part no rubbing at all and the tires aren't stretched.

[ken1137]

Nice ! Now we just have to get people to use this information (1010tires.com), or for it.

[Black Gold]

Originally Posted by BrokenVert

1010tire calculator is great - been using it for years


Let me change something quickly though. Your example 7.5 et 34 is a bit wrong.

I run 8inch et 40 wheels in the front which have the same position relative to the inner fender in front - and with a 225 it doesnt rub.

your offset calculates to exactly the same as my example, so it makes sense that it fits and doesnt rub (as predicted).

depending on the tire brand, i can see how even a 225 would fit (not much different than a 215).

i should have specified that i am talking about running 225 tires in the front and 255 in the back.

a lot depends on the size of the tires that you run.

Originally Posted by Joaco135

I run 18x8 et35 with 215/40 & 18x9 et40 with 245/35 lowerred on H&R springs without rolling the fenders and only rub slightly on big dips at fast speeds but for the must part no rubbing at all and the tires aren't stretched.

interesting

but you still do rub some, so the fitment isnt quite rub free.

the main purpose of this post was to show people HOW to calculate offsets though, and how to understand how the different wheel sizes and offsets will fit on their car. with that information, they can then determine whether that setup meets their goals or not.

you prefer a more aggressive setup than me, and seems like you did the reserach and understood how the fitment would apply to your car.

[BrokenVert]

Originally Posted by KennyPowers

a lot depends on the size of the tires that you run.

Indeed it does - those are my winter Dunlops that are 225.

My summer tires on the same size wheel and offset (again 17x8 et 40) rub slightly on dips.

Thats what I get for going with a 245 Star Spec in the front - to be rectified soon though. Yay camber plates, ha!