It definitely isn't enough tire
Which is why I'm going to a square setup with 19x9.5" rims and 255's all around at the very least. I can go wider (not as wide as the Z) but then I'm looking at large increases in unsprung weight. I've had traction issues on acceleration from day one with the stock 348hp. I partly blame the Bridgestones and the asphalt they use here but some of it has to be suspension geometry and OEM alignment specs. Can't imagine having C63 power and 245's in the rear.