What size spacers should I run with 245/40/17 in the rear?

[850 T-Gul]

I'm looking to run 245/40/17 continentals in the rear on the stock avus rims and was wondering what size spacers I should use back there to clear the rear suspension and line up nicley with fender but not stick out too much. 5mm, 10, 15? BTW I know 245 are a bit wide for the stock rim, but the continentals are not that wide of a tire compared to say an S-03 so I don't think it should be that much of an issue. I would just get 235/40 avs sport or S-03s but I only need 2 tires as the fronts were replaced a few months ago and want to have 4 tires of the same brand, and I think 235 continentals wouldn't be that much wider than the fronts and it would be silly to have the rears only 10mm wider than the fronts.Thanks.

[SuperbSantorin4]

I don't quiet understand your question. You are running a 235/40 cont. in the front and want to run a 245/40 cont. in the rear?

[850 T-Gul]

No, I am currently running stock size 225/45/17 on all tires but am going to switch to 245/40 in the rear and I am pretty sure I will need spacers for those. The front tires are just about new but the rears are worn so I would like to put wider tires in the rear for both looks and peformance. So with the new rear tires I will be running 225/45/17 front and 245/40/17 rear hopefully. Sorry for not being more clear.

[SuperbSantorin4]

You know I don't really have any advice about your situation b/c I havnt dealt with that tire size or spacers. But to be honest not only are you asking for trouble about fitment and clearence, but also I dont think it is going to help performance. If I were you I would stick with normal size tires with the same all around, if you want to go wider go with a new wheel set up. Sorry I couldn't help.