tires

[gfanning]

How wide of tires can you go with on 09 with H&R Super Sport Spring with 1.9 drop on back with no problems ?

 

[stkjock]

Depends on the rim. 295s should be no issue, even 305s

 

[gfanning]

FR 500 18"x 10 with +40 offset

 

[allworknoplay]

I run 285 on all 4 with 2 inch drop. With a 40 offset you might not clear front. Rear I wanna say you can fit a 305 on a 10 but I personally wouldn’t go over 285.

 

[RMB427R]

295 is where I would stop.

 

[Gabe]

FR 500 18"x 10 with +40 offset

The pic below shows a 305/40/18 Nitto 555R on a 18x10 with 42mm offset.
The 40 will push out the wheel 2 mm more toward the fender/outside of the car.

Ideally a 10"-wide wheel should have a 285 tire on it, they fit nice and square-shouldered with no bulge.

That having been said, I ran that combo above for a while with absolutely no issues, lowered in the back about 1.25", with an adjustable panhard bar to center the rear axle.

For a 40mm 10"-wide wheel though, I would not a recommend a 305 tire, since it's gonna bulge, you're really only gonna get about 275-285 of that 305mm on the ground, and it might also touch/rub the fender lip with the 40mm offset.
I had tire rub on a set of 20x10 40mm-offset wheels with 305/35/20 tires on them ... had to lift the back of the car with adjustable spring perches. Ended up selling the wheels and putting my regular springs back in.

Tire rub isn't sexy:

 

[Benwhite911]

From what I understand, if you have the rim for it, you can go as large as 345's in the rear. 345/35r18. However, I also recall reading somewhere on this forum, that rubbing at the bumpstop, if you go that wide and lowered, can present itself. I can't explain it myself, but the writer of it did make sense.

 

[Gabe]

From what I understand, if you have the rim for it, you can go as large as 345's in the rear. 345/35r18. However, I also recall reading somewhere on this forum, that rubbing at the bumpstop, if you go that wide and lowered, can present itself. I can't explain it myself, but the writer of it did make sense.

To run anything larger than a 315-325, bump stops need to be moved (yes, there's a relocation kit), the upper shock sleeves need to be trimmed or removed, and for the really larger sizes there's a bracket that needs to be removed on the frame/body, above the bumpstop area

 

[Pentalab]

The bump stops are not the issue, its that bracket that needs to be cut off. That bracket is used at the factory to lift the car down the assy line. The plastic sleeves that go over the top portion of the rear shocks also needs to be cut off ( gives u another 1/4" ). That bracket sticks out a bunch, easy to slice off. The biggest I have seen is a 335 MPSS, on 11.5" wide rims...on a 2008 car. It barely fits, with correct offset used.

A 305/315 on a 11" wide rim, at least on the 10+ cars is a non issue. Get too wide on the rears, and without a mating wide front, the car will understeer. Easily fixed with a smaller rear sway bar.

A 285 front on a 42mm offset is an easy fit..on a 10" wide rim. Go much wider than 10" on the front, and it's a bit trickier to get stuff to fit.