So why does nobody make 255/35/17 tires for staggered rims?

[sirius600]

I picked up a set of staggered contours (17x7.5 and 17x8.5) the other day and am now looking for some tires for my new wheels. Using the tire calculator, i like most here have found a perfect setup would consist of a 225/40/17 up front and 255/35/17 in the back. Nice and wide in the back while keeping the same overal diameter all around.

So why does no one make these tires other then in race compounds? Seems like a no brainer.

[LivesNearCostco]

One possibility is those tires would be smaller than stock diameter (about 25") for the BMW E36 and E46. To be in stock diameter, you would need 225/40/18 and 255/35/18, or 255/40/17, and maybe 225/45/17. If you look in those sizes, I think you'll find a lot more selection.

What is your stock tire size?

[sirius600]

Its either 235/40 or 225/40 depending on the wheel. 255/35 would be exactly the same diameter as a 225/40.

[LivesNearCostco]

That is correct, but 235/40/17 is 24.4" in diameter while 225/40/17 is 24.1" in diameter. (And according to the tire calculator I used, 255/35/17 is a hair smaller at 24.0" diameter.)

I would say go with something the same size as a 235/40/17 or even a shade bigger, like the 245/40/17, which is 24.7" in diameter. Yes it's a bit bigger around than your stock 235/40/17 stock size, but you'll get a much larger selection. Did you really want 255 width tires to fill out the wheelwell, or shorter than normal tires for better clearance? While I don't have an E36, my impression is that most of the E36 M3 cars at AutoX and track days are wearing 245/40/17, 255/40/17, 235/40/17, or 225/45/17.

Looking at what Tire Rack has in these sizes (including all season, winter, and runflat tires):
235/40/17 -- 15 results
245/40/17 -- 68 results
255/40/17 -- 55 results
225/40/17 -- 2 results (both track/competition tires)
255/35/17 -- 0 results
225/45/17 -- 165 results