A question about rim size and offsets

[narkosys]

Hello all!

I am looking at wheels and tires and I have to look at the 18 inch rims as my selections for a 315 tire in 17" are limited to 1 tire and the 18s give me much more options. I am thinking of shoving a 275/35R18 in the front along with a 315/30R18 or 335/30R18 in the rear.

The wheels I am looking at for these monsters are American Racing VN427s in 18x9.5 and 18x11. I am wondering what offset should I use? According to the offset calculator on 1010tires.com I am figuring 19mm offset for the front and 21mm offset for the rear. Is that right and will it fit? What about backspacing?

I was also looking at the FR500 in the 18 inch. I asked my local tire guy if a 315 would fit and he said no, yet I swear I have seen a few coupe owners who have a 315 on a 10 inch rim which confuses me. If it does fit then I could go with the 245/315 combo on FR500 rims which I also like a lot.

Thanks in advance,

P

[riptide motorsport]

Richard Oben's your man................he's the guru on wheels. He's vendor here on the forum: North Racecars

[CHOTIS BILL]

I am not sure why you think there is only one tire in 315/17 size maybe you need to look at different aspect ratios. Go to TireRack.com and shop by tire size and there are several different brands and types. I have the FF5 10.5 x 17 rear wheel with 315/35/17 Goodyear tires on the rear of my Type 65 and they fit fine. I am using 275/40/17 on the front.

Bill Lomenick

[narkosys]

I am looking at tires in my neck of the woods. I prefer buying local because I like supporting local shops and if something should go wrong I can go back and say FIX IT! Besides by the time you factor in the freight and brokerage fees those $300 Goodyears, Nittos or other brands have now become the same price as Pirellis.

Hence why I am looking at the 18. There are more options when it comes to 300mm+ range of tire widths. But I do go to tirerack and 1010tires to see what is out there and then look if they have them out here.

If I find something I like in the 17s, bonus!, because I really like the FR500s and it would make some things easier. But it is always good to have a plan B.

P

[jkrueger]

I will tell what I did. It may help you out. I bought the FR500 17x9 with +24mm offsets for all 4 corners. That wheel with a 275/40/17 fits real well on the front and looks right as well. So your +19mm offset should work there as well as it will be only 1/4" farther out than mine. See picture below. That is with -1.5 deg of camber.



On the rear, that wheel with a fox width axle looked lost in the big rear fenders. I also had a rub issue with my door bars that probably wouldn't be there with a stock frame, so we put a 1" spacer on the axles. The tire looks better and no rub.

JC