I purchased a 2008 Mazda 6 yesterday with stock 16" steel rims. I have a set of ADR Design rims from my old 03 Nissan Altima that I woulds like to use but the recommended size at Tirerack is 215/50R17

Specs:

17" x 7" 5 x 114.3 40mm with 215/55R17.

Can I get away with a 55? I understand the speed vs speedo rating would be off a bit but would it effect anything else or would the tires rub?

Also I believe on one website it stated tehat teh offset should be between 45 -60 would 40 be ok?

 

I doubt you would have any clearance problems with 215/55-17 tires, but you could be close considering you want to also use a wheel with less offset than recommended.

The 215/55-17 tires are the same width (215mm) as the standard tire on most 2008 Mazda6s, so no problem there. The combination you want to use would result in a tire that would rise approximately 0.42" higher into the wheel well than factory 215/50-17s...probably not a problem considering the clearances manufacturers build in to their stock wheel/tire combinations.

However, you are compounding the clearance issue by ALSO pushing the tire outward by AT LEAST 0.2" because of the smaller offset (45mm minus 40mm = 5mm = 0.197"). This assumes the factory wheels carry a 45mm offset and not greater - - again, 0.2" per additional 5mm of offset.

The result COULD be slight rubbing at the lip of the fenderwell, but my guess is you'd be OK.

I suggest mounting a 215/55-17 on one of your wheels and checking it for clearance on the front and then the back on one side of your car. Be sure to steer lock-to-lock while weighting down the front fender to simulate bumps.

You're right about the speedometer error - - the difference between the 215/55-17 and 215/50-17 is a difference in tire circumference of about 3.3%, which translates to about 2.3 mph difference at 70 mph. Since auto manufacturers build in roughly 2% optimism in their speedometer readings, you'd likely end up about 1% pessimistic - - no big deal.

The real question I have is why opt for the taller 55-series tire when the factory (and Tire Rack) uses/recommends the 50-series? The ride might be a smidgeon softer and fuel economy MIGHT be a little better (lower RPM), but you also risk these clearance problems.

 

I have about $1900 invested in rims and tires so I was hoping to use them, I tried selling them but I get ridicules offers of $400 for everything

 

So, just throw them on your 6 and see how they work out.