by atlanta solara » Mon Aug 19, 2002 7:24 am
not sure if you've gotten your tires already but if not, wanted to add on to the valuable advice already posted here.
if you want to keep odo/speedo readings accurate, and more important maintain performance in terms of acceleration, mid-range/top speed and economy, it's critical to stay as close to the original tires' "rolling circumference."
simply means travelling the same distance with the new wheel/tires as with the factory set.
tirerack.com simplifies this puzzle by providing complete technical info on the tires they sell. first click on a tire (same brand is best) that's exactly the same as your factory tire (205/60/16 or 205/65/15 on the factory Bridgestones if memory serves). Then click on "technical specs" or similar title and look for the "revolutions per mile" number for your factory tire size.
take note of that "revolutions per mile" number and shop for your new 18" tire in the other brands.
match the 18" tire closest to your "rpm" number and you've got your best possible tire size.
you'll see too that tires of the same size have different "rpm" numbers due to the brands' particular way of constructing their tires.
on tire lifespan, the higher the "upqg" (may be off one letter) or "treadwear" number, the more miles you'll get out of the tire. generally, you won't get as much miles out of the 17' and up sizes as you would the 16' and below because of the performance/handling orientation of the larger tires. so, you'll want to compare the upqg numbers of your tire choices if tirelife is important to you. my guess is that you won't see anything higher than 300. the smaller tires have a number as high as 460 (50k miles or so).
but life is a compromise especially with tires. depending on your priorities, you can get a quiet tire that doesn't get as much miles as one that's noisier and that's ok. or you can get one that corners real well but is jarring on rough surfaces. mix in all the other excellent suggestions by other folks and you'll ride confident.
my 2 cents' worth. good luck.
