quote:The reason you want 15" is that they are priced cheaper. The diameter size of the wheel does not have anything to do with the width.
Go here: http://www.miata.net/garage/tirecalc.html
IMO, you don't need anthing wider than 195mm for a Camry. IMO, 195/75/15 would be best buy.
This is slightly misleading. The diameter and the width are most definitely related, via the aspect ratio. The height of the tire is the width (in mm) times the aspect ratio (e.g. in 195/65/15, the "65" means 65% for this calculation, so that the height of the tire is 65% x 195 mm = 126.75 mm). The total diameter is the rim diameter in
inches (the "15" in 195/65/15) plus 2 x the height.
I really have never quite understood why metric and imperial units are mixed in tire sizing. FYI the total diameter of a 195/65/15 tire is 634.5 mm (you convert the 15" wheel diameter to mm). The diameter of 215/60/16 is 664.4. The diameter of 205/65/15 is 647.5. So if you went with 205/65/15 your total diameter would be
smaller than stock by 2.5%. You'll have to ask the experts if that's good enough (it will affect your speedometer and possibly stress some steering components. Should be ok though). But, as you have been warned by others, a 15" wheel may or may not fit over the brake assembly so check first.
Narrower contact patch in winter = more psi to "cut through" snow and ice, at the expense of dry handling. The reason you can't drop to ultra-narrow tires is that you still have to meet the load rating spec.