[peteranton]

I just bought used 20" Style 361 wheels for a '13 328i Sport. I thought I would be able to use the mounted PZero RFs for this summer, but decided on new tires. To my shock and amazement, the set is $1500 (the 255/30 rears are $500 each).

I'm looking to going to non run-flats - my wife is not crazy about it- at the staggered 225/35 and 255/30 sizes, or going to a 235/45/20 square setup to get "reasonable" run-flats.

Besides the speedo correction/0.8" taller, the only other issue that the TR rep had was an engine gearing ratio issue. What is that, and has anyone done a square setup with 20" x 8"/8.5" wheels on a F30?

[.BMW.]

Something is wrong with your numbers, 235/45-20 is a SUV tire.

But 245/35-20 square will fit fine on staggered 8/8.5" wheels.

You might like to add rear spacers to match the more aggressive front wheels.

[peteranton]

Originally Posted by .BMW.

235/45-20 is a SUV tire.

Sorry, 245/35

Thank you...Outside of seeing more rim on the back, any issues with how the tire will look on each rim (Front/back)?

Also any thoughts on the "engine gear ratio" and why that would matter on a 0.8" (2.032CM) taller tire?

[.BMW.]

The rear tire will be slightly more stretched, that's all.

I think he meant since 245/35 is 2% taller than OEM the engine will use 2% lower rpm for a given speed. Nothing to worry about.