Hey gang, my Work wheels are showing up this weekend and I'm trying to get some rubbers and wondering if anyone has recommendations in sizes. The rims are work vs-xx Front 18x8.5 +45 (A Disk) Rear 18x10 +45 (O Disk). They will be riding on Ohlins, and the main requirement is that they don't rub and i don't have to roll the fenders. Any suggestions? Thanks for your help in advance!

 

I just went down a similar path last year, but ultimately ended up rolling fenders and adding camber. It's no fun pulling your front fender lip down. There just isn't much room under the front fenders!

What is your camber? I would dial in -1.5 degrees minimum as insurance up front before mounting anything.

Main concern up front is keeping the tire diameter under 25" and avoiding wider then normal tire section width. Tire section widths can differ between brands.

I would run 245 35 18 up front on the 8.5 wide wheel.

275 35 18 or 285 30 18 in rear is pretty standard for an 18x10. With the 285 30 18 your rear diameter will be pretty close to the front 245 35.

 

So you don't think 245's up front will rub?

 

You didn't answer the question on camber.

It sounds like you just want a go or no-go, but it's not that simple. I think a 245 35 will probably fit without rubbing under most conditions. It depends on the tire's actual width and your camber. **** gets tight with the wheel turned and suspension under compression.

 

Sorry, the Ohlins are going in at the same time and we've not decided on any settings yet. I guess it could be a chicken and egg issue. To give more context, it is a 94' Chase White base with 20k miles, so I will unlikely be tracking this thing any time soon. That means we are not setting the car up for performance, but more for aesthetics and durability/longevity.

 

Mazda's rule of thumb for tire sizing, turns out to be just about right,

205 tire on a 7" wheel, 225 on an 8" wheel, 245 on a 9" wheel, and so on.

on a half size, like the 8.5, it depends on the actual tire, they vary. for instance a 205/50/15 Hoosier R6 was wider than the 225/45/15 Toyo...

 

Negative camber gives you clearance at the front fender wheel arch. If you use the factory settings when you get it aligned (which actually specs positive camber IIRC) you will be giving up a ton of clearance/insurance... not to mention performance.

Even if you don't plan to track the car you will probably hit a bump with the wheel turned at some point.