Since I've had 17s, I have run through 2 sets of different size tires.
255/45/17 Firestone SZ50 <<< AWESOME summer only tire. Thumbs up if you live in a no snow / ice area. 9/10 points overall, IMHO.
245/45/17 Dunlop SP5000 great all season tire. Although not particularly excellent at any one thing. 7/10 points, IMHO.
The 245/45/17 is slightly over 3% speedo error, while the 255/45/17 is slightly under 3%.
Most tire guys will recommend not going over 3% because you may affect your gearing and you will affect your odometer readings at that point.
_________________________
Regards,
Chew
2007 Sly Silver Pontiac Solstice GXP