I need new tires and may go up a size on my 2001 SE with the 215 55 16" tires to 225 55 16" or may buy the replica 01 SE 17" wheels and 225 50 17 tires to match. 2 questions- what do you interpret the treadwear rating numbers? and anyone go up a size having problems with rubbing tires in the fenders?

 

Go to tirerack.com to get info on reading tire specs. And no, you won't experience rubbing with either of your choices. But if you're going to upsize from 225/55R16s and stay with a 16" wheel, you should consider 225/50R16s rather than 225/55R16s.

 

And as fellow member y2kse's sig points out, do a search re: 225/50/R17 choices (very limited to say the least). You'll find most of us stuck with the OEM 17s wish they were at least half an inch wider...

 

Treadwear numbers are simple. The higher the number, the slower the tread will wear. A 160 treadwear will wear faster than a 300 treadwear and so on.
Initially, the numbers are based on 100 (the standard tire). So a 160 treadwear tire will wear 1.6 times slower and a 300 treadwear tire will wear 3 times slower, etc. Nowadays, all tires except for R compound racing tires have treadwear ratings of above 100.
My R compound Kumho ECSTA V700 racing tires have a treadwear of 50
They last me 2-3 races.
My Bridgestone RE730 have a treadwear of 300.
My Nokian NRW snow tires don't have a treadwear rating because snow tires aren't required to have UTQG ratings.

Check out http://www.etires.com/talk.html for a decent tire FAQ.
Tirerack's tire tech site is excellent as well: http://www.tirerack.com/tires/tiretech/general/utqg.htm

 

I have the 16 x 6.5" with 225/55 R16. I got BFG G Force KDWS at around $100 per tire. It is not the Michelin Pilot Sport, but it is a great improvement over the stock Toyos (changed at 32K slipping and sliding. The budget was not there for the Pilot Sports with a small child on the payroll and a stay home mom.

As mentioned before, check out the tirerack.com.