Mar 7, 2017 update to the BMW M3 project car

Squaring Up Our M3

The E46-chassis M3 came stock with a staggered wheel and tire setup: 225/45R18 tires on 18x8-inch wheels up front and 255/40R18 tires out back 18x9.0-inch rear. Somewhere along the line, our car picked up some Bremmer BR05 wheels in the stock size.

However, 225mm tires are kind of narrow for a 3400-pound, 333-horsepower car. Let’s go a little wider—and while we’re at it, can we square up things so we’re running the same tire at all four corners? Yes, we can.

Our solution is a 255/35R18 tire at all four corners. To make those tires fit, though, our wheels will remain staggered: 18x8.5-inch fronts and 18x9.5-inch rears.

We’re prepping this car for the real world—mean street use—so we wanted a tire that was quick yet comfortable. The Toyo Proxes T1 Sport seems appropriate. It’s an ultra-high-performance summer tire that carries a 240-treadwear rating. It’s not going to be as fast as the brand’s Proxes R1R, but it should be a tad more civil, too.

Wheels will be the TSW Ascent in the brand’s matte gunmetal finish. It’s something that’s looks a bit more contemporary than our current setup yet won’t break the bank. These wheels, in our sizes, retail for about $250 each.

All of the parts just arrived at our office, but the TSW Wheel Configurator gives us an idea of how everything will look.

And the lowered stance? We have been talking to Bilstein about that.

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Comments

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doc_speeder
doc_speeder HalfDork
3/7/17 8:48 a.m.

I did this on my G35 coupe. It really changed the handling balance nicely. It was very neutral after the change, without changing springs, dampers, or sway bars. And makes tire rotation possible, at least for me as I was running the same width rims all around.

klodkrawler05
klodkrawler05 New Reader
3/7/17 9:52 a.m.

I'm curious, what's the reason for switching to a square tire but keeping the staggered wheels? 18x9.5 square is a very common square fitment for a e46 m3, 18x10's fit under stock fenders with the right offset and alignment.

seems like a 18x9 square or 18x9.5 square setup would give you even more front grip and have the added bonus of being able to rotate front/back without paying a shop to dismount tires and put them on the opposite wheels.

dyintorace
dyintorace PowerDork
3/7/17 1:04 p.m.
klodkrawler05 wrote: I'm curious, what's the reason for switching to a square tire but keeping the staggered wheels? 18x9.5 square is a very common square fitment for a e46 m3, 18x10's fit under stock fenders with the right offset and alignment. seems like a 18x9 square or 18x9.5 square setup would give you even more front grip and have the added bonus of being able to rotate front/back without paying a shop to dismount tires and put them on the opposite wheels.

I had the exact same thought. If you're buying new wheels, I would think you would go with a true square set up. Otherwise, you still can't rotate front to back easily.

rslifkin
rslifkin Dork
3/7/17 2:32 p.m.

Heck, I've known people to run 4 of the stock M3 rears with 265s on them without issue. There's a good bit of room to play on the E46. Even the non-M sedan (the worst of the group for tire clearance) fits square 255/40R17s on 8.5s just fine.

200mph
200mph New Reader
3/8/17 10:41 a.m.

These look much better on your car than as boxes stacked in your office taking up valuable space that could otherwise be used for more clutter...

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