A tack in the sidewall took out a front tire last week, so I finally caved in and replaced the entire set (along a new set of TPMS sensors).

Old: Bridgestone Potenza RE040 225/45ZR18 (Stock)

This is what 10 year-old, low-mileage rubber looks like (in addition to being hard and prone to skipping and rumble noise)

New rubber: Michelin Pilot Super Sport 245/40ZR18 (links to reviews below)

The new tires are 2 sizes wider but actually fit the stock rims better in my opinion, the sidewalls are more vertical and the profile is squared-off. Though it seems to be the trend to supply slightly narrower tires in many performance vehicles, since it provides a stiffer sidewall and lower weight. The smaller aspect number (40) ensures the overall diameter doesn’t change (difference is about 0.3″) so speedometer error should be minimal.

First impressions: Soft-compound summer tires are nice. Road noise is much reduced, and feel much grippier on launches and braking. Now I just need to take them up to speed to check balance, and a few turns on Mulholland this weekend to try out the cornering. Well, maybe not, this being a holiday weekend. Besides, there’s something very cool arriving Friday (hopefully).


Much thanks to Cody at TireRack and Kami and Bill at Royal Motors.

Michelin Pilot Super Sport – Reviews:
Car and Driver – First place: Monsters of Grip
Road and Track – Review: Michelin Pilot Super Sport Tires
Motor Trend – Testing the Michelin Pilot Super Sport