I wouldn't run 275s on a 8.5" rim. It's outside the manufacturers minimum specification.

If you want to run 275s, I'd recommend picking up some coupe 19s.

 

275 is definitely too wide for sedan duckfeet. 255 is not as that's what I've been running for the past two years.

 

The Michelin A/S3+ has been reviewed by Tire Rack after looking at it the three best a/s are the Michelin, Pirelli P Zero A/S, and Conti DWS 06 I bought a used pair of the A/S 3 the grip was great, but the tires had a vibration problem with them, I am not the only person to feel this as well. I thought I had a bad rotor once they came off, the rotors felt fine. The A/S 3 IMHO took bumps worse than the PSS.

I don't need a/s tires, but their testing puts these three up there with the PSS, yet the should last longer. I can't wait for them to review the General AS-05, they should be a good improvement over the AS-03, they are priced at 111 and 125 in the 225/245 18s, so the price is very good, if they are close to these three in Dry and Wet grip, they most likely will be my next tire.

I remember in the past having tires with higher treadwear and they didn't have the grip of the those with lower treadwear. I wondered how much actual extra life I would get out of them when they would slip and spin more often. These newer tires don't have that same feeling, they feel like they have much more grip, I wonder how accurate is the treadwear rating.

 

@blnewt

So you got me thinking. By going with the larger width but same aspect ratio, the diameter will increase slightly (~.4" or so) as will width. Wonder how this will translate in terms of handling? The PSS feel like they have ever so slightly more sidewall flex than the oe RE050a's. Not enough to be an issue or concern in corners. Not sure I'd want any more than that though.

 

I think having just a bit wider contact patch would make up for the slight increase in sidewall flex, and the new Contis seem to have stiffened up the sidewalls significantly.

I'd shoot a PM to Furlow & ZahyMatar, both just bought sets of them and should be getting some good impressions by now on how they are performing. Looks like inkognito in reply #11 is singing their praises too!

 

So I've been running these tires for about 3 weeks now on my 2013 G37S 6MT Sedan. My current setup consists of 19x9.5 Forged NISMO Rays with 255/40/19 Continental ExtremeContact Sports. Along with Stance XR1 true-type coilovers, 12/8k Swift springs, SPL FUCA, SPL rear camber arm, SPL rear toe arm, SPL lockout kit, Cusco FSTB, Hotchkis sways and Moog end links.

The car handles like it's on rails with the square tire setup. This is my 2nd set of summer tires on this car (Came with Potenzas from the dealer) and I find these to be a great compromise with comfort/handling. I've noticed that these tires excel in wet conditions (I live in coastal NC so it rains A LOT). They are VERY quiet and I don't think I can recommend these enough. My other two options were going to be Michelin PSS and the BFGoodrich G-Force Comp 2 Sports.

I don't think you can go wrong with either, but these Continental tires seem to have copied the tread pattern from the Michelin PSS and have maintained the treadwear/cost of the BFG Comp-2s. This is exactly what I was looking for in a reasonably priced tire. I paid $204/tire for 255/40 and have no regrets whatsoever.