I have a question: What should the offset be when you switch to a wider and bigger rim, like from stock 6x15 to 7x17. Should the offset remain the same or should it decrease or increase for optimal handling? And what is the stock rim offset?

This is on tirerack's site: "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. Our extensive database allows our sales staff to offer you the perfect fit for your vehicle." http://www.tirerack.com/wheels/tech/offset.htm

Thanks.


[Modified by EuroITR1689, 1:03 PM 12/17/2001]

 

Yes, the offset changes when you go to a larger width. The offset differs slightly from a manufacturer to another. I believe with 7"x17" common offset is 38mm. However, that is just one offset that will worth with 7" width... sometimes there are 42mm offset. The obvious thing to check is the clearance issue regarding the brake caliper with respect to the wheel spokes and the control arms with respect to the inner lip.

Once you go with a larger sized wheel, you should adjust your camber and toe settings to get the most out of your wider settings.

 

On the ITR, you want to go with a pretty high offset, even with a wider wheel. The steering geometry is designed around +50mm offset, and that won't change with a wider wheel. Offset is the distance from the centerline of the wheel/tire to the wheel mounting surface, and if you go with something like a 38mm offset, you'll get weird handling. The contact patch will be farther out from the car than the smart people at Honda intended. I have 16 * 7.5" with +45mm offset and it is fine, but i wouldn't go a whole lot lower offset than that, regardless of width or diameter of the wheel.

 

I run a 225/40-16 tire on a 16x7" rim with 50mm offset. I have no rubbing/contact that I can ascertain.

 

Thanks for the answers. The stock rim has a 55 mm offset, right?
The Accord Type R rim has a 50 mm offset (7x17). Maybe I will get the white ones........

 

Stock USDM ITR (15x6) Offset is 50mm, not 55mm.

 

Oh, maybe I am confused. Then the ATR rims have a 55 mm offset.....

 

Maybe... we don't get the ATR here. Preludes (also with the H22A like the ATR) have +55mm offset. I used some Prelude wheels on my ITR and it felt a little squirrelly in the steering. They would be perfect with 5mm H&R spacers though.

 

What do you mean "squirrelly"? "Integra Rated R" from Iceland has ATR wheels on his ITR......