I've found a set of wheels I like on special, but the front wheel offset is +25mm. From what I've researched, we need +40mm. That's only 1.5 cm difference right?

But I digest,
What will work?????

 

Unfortunately there is no exact answer, it partially depends on what the width of the wheel is, what width tire you're putting on them, and how you can live with the wheels/tires pushed out really far to the outside of the fenders. Generally something in the 35-50mm range will be best, the stock 17x8 S197 wheels are 45mm offset, and the stock 18x8.5 S197 wheels are 50mm offset.

The 25mm wheels you're looking at are basically an inch off (will stick farther out) of the stock 18" 50mm wheels, but if they are only 8" wide and you won't be putting anything wider than a 245mm wide tire on them, they'll probably work. A 25mm offset wheel is really for an SN95/New Edge Mustang though.

The wheels I'm using for autocross on my '08 GT are Enkei RPF1's in 17x9 with 22mm offset, along with 265/40 Dunlop Star Spec tires. They are pushed out to the very edge of the outside of the fenders, and stick out past just a tiny bit in back. The only reason I'm using them though, is that I already had them from my '01 Bullitt. I'll eventually be switching to something with a more appropriate offset, I've got my eye on some 18x9's that are available in 35mm or 45mm offset.

 

I plan on keeping my current tires since they are new. I currently have the 18" wheels, and I'm looking to put 9" up front and 10" in the rear. So with that being said, then front offset can be anywhere from 35-50mm, and rear 40-55mm? But the "sweet spot" would be 40mm?

I really don't want them to be poking past the fender, I'd like the more flush look.

EDIT: Oh, and the tires will be 245/45/18 up front and 275/40/18 in the back.

 

Its too bad your RPF1's aren't 17x9.5 in that offset. I'd be offering you some money!

 

Unfortunately the class I autocross in limits me to a maximum of a 9" wide wheel. I might be moving up to an 18x9 Enkei RPF1 or PF01 next year.

 

RPF1 in SBC is

 

Which class do you run in?

 

STX - max of 9" wide wheel, 265 max tire width, street tires with treadwear of 140 or higher, no race tires.

 

I'm thinking of moving down classes to an ST class from ESP. My competitor today at Dixie Nationals was running 315 Hoosiers on all four corners. They made my 275's look like bicycle tires. He was 8 seconds quicker than me. Drifting on street tires is fun, but it's slow on course. Glad to meet another autocrosser here.

 

Yeah, I ran 275 Hoosiers and Kumho 710's on my '01 Bullitt for a few years when I autocrossed it in stock class, then the Shelby GT's started showing up with 295 wide race tires (and more power and better suspension) so I thought I'd give STX a try with my Bullitt first and now my GT. It is still an uphill battle, but a lot of fun locally with usually 10-15 cars in the class.