Originally Posted by nachob
295/30/19 is closer to the correct diameter than 285?
On a high revving NA car a smaller diameter can help the car spool up faster and get into the power band, but that is not an issue on the 1M. If anything, going with a smaller tire will cause you to reach the redline sooner and having to shift earlier.
I see a Michelin Super Sport on Tire Rack in 295-30-19 which can fit 10-11.5" wheels. Good luck.
There are members who posted recently (I remember at least RobertM) that 295/30 really fits with zero complications both on the stock wheel and inside the wheel well. And yes, as a set 275/30 19 and 295/30 19 is extremely close to stock, and I believe it will create no DSC issues at all, the balance will be almost identical. You are going +3 all corners in width while dropping from profile 35 to 30. 295/30 has 26.0 inch diameter while stock 265/35 has 26.3. 275/30 has 25.6 vs. stock front's 25.8.
I also contacted with a few E9X M3 guys who reported use of this set up on stock Competition (1M) wheels and they seem to be very happy, no issues.
"The mark of a great car is one whose overall competence exceeds what you should expect from its individual components and the 1M does just that", Chris Harris.
BMW 1M-SOLD-: TECH: Evolve Race+N55mids, Evolve IC, Michelin PSS, ER cp, aFe filter, CDVx, Vorshlag camber plates, BMS OCC EXTERIOR: trunk spoiler, blacklines, black grills, IND goodies INTERIOR: Alcantara steering wheel, steel pedals, custom mats, MPower e-brake.