My wife isn't all that happy with the ride of her '07 6s - feeling bumps/ruts in the road a little too much. It's also time to replace the summer rated (215/45/18s) with an all season tire. Was thinking about going with a 215/55/18 tire size as an alternative. Will the larger profile improve the ride a bit (ie., more cushion between road and wheel)? Can I go with a 215/50 size instead? Any worries about either of these sizes and rear wheel well (inside) rubbing?

Also not sure if this has been posted before - but here's a nice tire size calculator. Has a look-up feature using Make/Model/Year input for showing the stock tire sizes...

TIRE CALCULATOR

Wow, definitely do not go that size.

18" wheels/tires are not known for their comfort level. Going with a 225/50/17 setup would probably do you a LOT better.

Yeah, if you want a softer tire with a larger profile you'll have to go down to a 17" rim.

You could probably find a 15" wire wheel that fits and get some 80 series whitewalls for the ultimate in gangsta comfort. Just sayin.

The 215/45/18s that came on the car from factory were all seasons, not summers. Unless you got the car used and the previous owner already changed them.

I wouldn't suggest changing the aspect ratio, such as changing the tire to a 215/55/18, if for some reason that doesn't rub, your speedometer would be significantly off. you would only change the height of the tire by about 4 mm but you could get a 225/45/18 and that would give alittle more cushions. Also see what speed rating the tire is, look for lower one such as h and v.. hope this helps

Every tire rides a bit differently. You might look into reports of ride comfort from tires that are the same size as what you're now running. For example, I have 17" wheels on my 6, and a set of Michelin Pilot PA3 winter tires rides much more smoothly over bumps and the like, and is far quieter than the OEM all-seasons. The sidewall is probably more flexible.

more tire sidewall will cushion road shocks better. the 215/50x17's from the earlier Mazda6 regular sedans will give you that slightly softer ride. 55 aspect tires are going to probably be larger in diameter and throw your speedo off a bit more.