Victor, the reason a 17" or 18" rim will have more clearance between the struts is because the strut angles away from the wheel, so the larger the rim diameter the more clearance there is between the struts, for a given offset....simple geometry my friend.

so does that mean i can run an 18"x 8"??? and get away with it after I lower my car a bit??

I've got to admit, this opens some doors on more wheel options. After reading Tom's reply, I did a little searching. Now Volk GTP wheels are beautiful, but I'd never think there was an application 17X8 @ +16 with an 8mm spacer - 17X9 @+15 with a 3mm spacer and you got Tom's fittment but, with 64 mm of glowing polished dish!

Of course that wheel set is dam close to 3 grand, but I guy can dream. Right?

so does that mean i can run an 18"x 8"??? and get away with it after I lower my car a bit??

I don't see way not, provided you do your wheel/tire location calculations correctly. Once you get past 8" rim width, you will be getting near the limits of acceptable clearance. You will most likely be running 35 aspect ratio tires....225mm wide to 245mm wide.

okay...first: what is the widest tire you can put onto a 7.5" wide rim? 7" wide?

will a 15x8 with 15offset fit without rubbing with coilovers?

You can fit 8" wide rims under the stock fenders with coilovers. You should roll your fenders for maximum clearance. I used to have 16x8, 5" backspace with 245/45-16 tires.

Now I am running 17x9.5 with 255/40-17 with flares only in the back.

okay. thanks for the info. i also wanted to know what size tires would fit on a 7.5" rim.

on a side note, i see that you are in hawaii. i am moving there next winter (oahu), do you know if there are any plans to reopen the speedway or if not build anotherone??

225mm tire is the most popular for that size rim.

Everybody is working hard at either reopening the raceway or building a new one and leaving the old raceway open until the new one is built. I have vested interest since I am the SCCA Solo Chair.

Thanks for the help on this...18 rims..here i come...going to get a nice set of deep dish rims

I am still confused on the offset of the rims. so if there is 0 offset the hub is in the center of the width of the rim? so a +15 offset would move the rim to the outside 15mm or inside 15mm?

------

===|

------

is this positive offset?

(i know the pic is not accurate but just for argument's sake)

From the tire rack...

The offset of a wheel is the distance from its hub mounting surface to the centerline of the wheel. The offset can be one of three types.

Zero Offset

The hub mounting surface is even with the centerline of the wheel.

Positive

The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front wheel drive cars and newer rear drive cars.

Negative

The hub mounting surface is toward the back or brake side of the wheels centerline. "Deep dish" wheels are typically a negative offset.

If the offset of the wheel is not correct for the car, the handling can be adversely affected. When the width of the wheel changes, the offset also changes numerically. If the offset were to stay the same while you added width, the additional width would be split evenly between the inside and outside. For most cars, this won't work correctly. We have test fitted thousands of different vehicles for proper fitment.

Will

This is why I don't like to use offset. The offset changes with wheel width where as backspacing stays constant.

Could I fit 14x9 with-26mm offset to the rear with standard springs or would I have to cut the arches and fit flares?

Nick