I need to replace the tires on my 04.5 S40 T5. I have the OEMs on them, but I burned through them in less than 20k. The OEM size seems to be 205 50R17, though online, such as on tirerack, it indicates that there's a second option size of 205 55R16. The later is much cheaper of a size and seems to be more widely available. Is there any problem with going with the 205 55R16 instead of the 205 50R17? Thanks so much in advance for your input.

 

The 17 (the last number in the tire size) is the rim diameter. So if you currently have 205/50/R17 on the car then no, the 205/55/R16 will definitely not fit your car.

I just put a set of Riken Raptor (made by Michelin) on another car of mine. I found it in a 215/50/VR17 (slightly wider than what you may currently be running, but not so much that it would create a problem) at www.onlinetires.com for $86 a tire. You might want to look into these. So far I have been happy with mine.