by atlantasolara » Fri Dec 27, 2002 6:53 pm
tirerack.com provides info on "revolutions per mile" per tire if you clicked on the "tire specs" (or something like that) link accompanying a tire model.
after looking at the specs, you'll realize that tires of the same size don't necessarily have the same "rev per mile" due, i believe, to tire design & construction that differs per make. the differences, however, are minimal.
anyway, the "rev per mile" number should provide a very good reference point for choosing tires of any size. just look up the original tire brand's rpm and search for your desired tire sizes (17, 18, 19 etc.) which match that original rpm number.
i believe for our cars the 215/50 is closest, with the 225/25 being next for the 17" size.
for those to whom tire lifespan is important, the treadwear number (denoted with a "upqg" number, might have jumbled a letter or 2) will indicate the mileage expectation of a tire brand/model/size.
generally, as the aspect ratio (the "50" in a 215/50/17 size) decreases, mileage declines and tire price increases. since there's a lot of driving here in atlanta, i chose the highest treadwear number available from 17" up and ended up with a 215/50/17, good for approximately 36k miles (with treadwear of 300). some tires have a treadwear index of 180, and this will be good for the short-distance user.
another consideration is road condition - shorter sidewalls (from lower aspect ratio/bigger rims) may mean driving ultra carefully to avoid potholes and other street hazards from denting the rims.
hope this helps.
