What tire pressure you running?
 

I did a search on here, with no results, and on google and got many different answers....it's seriously not funny. I own a '13 Coupe with the sport package option. I have the 7 spoke 18" AMG wheels, which from what I have found, fronts are 18x8 and rears are 18x8.5. Tires are 225 40s and 255 35s. The sticker in my fuel door says 30lbs front and back. I find this to be low. The sicker in the door jam says higher amounts, but at max loads. I tried the 30/30 and the car feels sloppy and squirly at highway speeds. Not good. Gonna try 33F & 35R, like I had in my BMW 328i coupe W/same size wheels and tires and see. Any chime ins would be greatly appreciated!

Grazie!

Simular equipment and options on my '12.

Running 35 front and 38 rear.

Getting 33 mph on freeway

Pretty happy with feel of the ride.

Thanks! I adjusted pressure and not a whole lot better. I am thinking this is gonna be suspension issues and not the tires. Body roll feeling too much. probably bushings and such. I recently purchased the car and have a good extended warranty. Time for the dealer to take a look I think!

I have the 17" 5 spokes and my tire recommended tire pressures are 33 up front and 42 rear.

This is with the stock 245/40 on the back. With my rear set to the 33psi recommended for the front the side wall was warping a bit right in front of the contact patch.

I'd imagine that your rear tires would need less than 42psi having shorter sidewalls. 38-40 I'd think would do well.

Here is a pic of my tire pressure sticker on the fuel door. The 30/30 is for normal load, which I figure just me or me and my wife would fall under. The 32/41 is for max load, which I take as 4 passengers and a full trunk. Anyway, I am sure I am having issues with some suspension bushings. What I am feelin is not my tires. I have new rear tires and fronts are worn but not dead. I am feeling a lot of side to side slop. It will get addressed though! :y

I usually drive with 35-front and 38-rear.