I'm currently on 255 on my G37xS, steering wheel is stiffer but that is something that I like, it drivers perfectly fine, just tends to follow the road a lot more than for say the 225 which is prone to happen but you get used to it. It corners a lot better, but I did have to up my psi to 40, at 35psi the car was floating around a lot more, since 255 is more ideal to run on a 9" rim, than a 8.5" rim.

 

I'm the opposite. The steering was always too heavy from the factory for my taste to begin with and the added heaviness and the other stuff was just too much. Stickier tires will also make the steering feel heavier. All things being equal, skinnier tires will do better in the snow too. Just stick to the size that came from the factory. At least that's what all the experts say. The engineers chose that size for a reason.

 

From what I've seen online, the stock 225 is the minimum width for an 8.5" rim, and the "ideal" widths are 235 or 245, with 255 being the max. The diameter works out closer to stock on 255/40 than 245/40, which is why I was thinking of going that way. I don't like how on with the stock 225 setup the rims protrude out noticeably further than the tires. I feel like that is asking for trouble in regards to scraping the wheels on curbs etc.

I had placed an order for 255s but now I'm on the fence and thinking of changing my mind to 245s as the steering on 225s definitely feels stiff already, not sure how much stiffer I want it.

 

I'm thankful someone revived this thread. I'm not a fan of the stock 225's - they look weird with the tread so much narrower than the rims.
I'm hoping someone will share pics or opinions on how the tire shape looks on the car.

I read on another discussion where they felt the 255's made the steering feel too stiff. Look forward to updates on your experience.

 

I also have a g37xs, and I'm in need of new tires. I was planning on getting 245/40ZR19/XL pilot sports a/s3 for all 4, and run it squared. But before I pull the trigger on it, I wanted to be sure it will work and fit properly on stock rims and height. Thanks in advance.