My MCS will be arriving shortly and I would like to get wheels for autocrossing. I see in the adds and the MINI specs that show about 50 for my stock 17 inchers to 40 for some of the wheels from various venders. What do these numbers mean exactly? My SCCA rule book shows a + - .25 is OK for the stock classes. What number gives the widest stance? Would one number give more clearance in the wheel well? Thanks for the help. :???:

 

The best way to go to remain in stock for SCCA is a 44mm offset. The .25 inches will work with a 44mm as the stock offset in a 17" or 16" could have been a 48mm.

The hot set up is the AK Tires Monza, but you could also just use the V-spoke (as it is quite a bit lighter than the S-lite), you will lose 8mm of track that way however.

The stock wheels go like this:

S-Lite (R85) 7x17" 50mm offset 25 lbs
V-Spoke (R84, X-Lite) 6.5x16" 48mm offset 17 lbs
R90 7x17" 48mm offset 24 lbs

Then there's these:

MINI-Motorsport Monza (AK Tires) 6.5x16" 44mm offset 13.9 lbs

OK, rereading this post, it looks a little scattered, but I hope it helps anyway - I need some sleep

Randy
randy@mini-motorsport.com

 

Randy,

If the stock offset is +48, and a -.25" difference is approximately a -6mm difference, the minimum offset is 48-6=42. If this is correct, can I use a 42 offset wheel? Or is there some other rule that limits the change to 4 mm.

Thank you,

Ricardo

 

I believe the ruling for stock class is plus or minus .25 inch from the offset of the factory wheel. .25" is about 6mm. So if you were to use the 17x7 wheel you could have no less than 44mm offset and no more than 56mm. 44mm being a wider track. If you went to a 16x6.5 you could have a wheel with an offset anywhere between 42 and 54mm. The R90 17x7 is a DEALER option correct? if so, you would not be allowed to use a 42mm offset 17x7 inch wheel as the FACTORY wheels were 50mm. If the R90's are in fact a Factory option, than 42mm would be legal.

Fred

 

I believe that on the MCS, nothing other than a 16x6.5 is legal for stock. The 17" wheels are a dealer option, and not legal for stock competition.

Don't worry about it too much if you are just getting started. Eventually, you'll want to spend the $1920 for Hoosiers and those light SSRs, but before that, you'll want to first explore using your street wheels and tires, then only after seeing what the experienced drivers do, go get the Kumhos (a lot less than Hoosiers, good enough for all but the very hottest competitors, and wear very well).

The AK wheels are a great deal, but I picked up a full set of 16x6.5 stock heavies with street rubber for less than a single SSR and half a Hoosier would have run me. (EBay rocks!) The street rubber will come off the stock wheels, go in the basement, and the Kumhos will be mounted up. Not light, but very sticky, wears well, cheap, and stock legal. I might even beat a WRX with them!

 

The 16x6.5" +48 offset V-Spokes (aka X-Lites) are stock wheels on the MCS. The 17x7" +50 offset S-Lites are factory options and are part of the Sport Package. I believe that Chayse's post is accurate.

The R90s are indeed a dealer option and therefore, 17" wheels must be limited to the 44-56mm offset range.

 

Guys, check out this link, it's been amazingly useful for me!
Wheel Offset Calculator

Good Luck,
Ryan

 

Or if you want to test various wheel and tire combinations, do a Google search for the keywords: wheel tire combination offset.

One site I have used is Tire and Wheel Combination Calculator