rock

Does anyone know if it would be safe to replace the stock 215/50 17s with 225/45 17 tires? We have 6.5" wide rims on the TLS. I was recently looking at several tire brands. I think the recommended width was at least 7 or 7.5". It would probably be a while till I change any tires since the stock Michelins have a pretty high treadwear rating. It would be nice to have wider tires and keep the stock rims.

JTang

Those are my sentiments too. I'm looking into new tires some day and I wanted to get a good sticky to get better traction. I was looking for the original size and wanted to see what was out there. I'm sure there is a discussion under the "Tires&Wheels" forum.

csp33

Well for stock replacements, I'd look at the Toyo Proxes T1-S, they offer tires in 215/50 sizes and I believe they're the same tires used in the Speedvision Touring class racing as seen on Speedvision.... I think those tires ar epretty good....

rock

Thanks. I found some good info on the "Tire and Wheel" forum. I might just stick with 215/50 17s just to be safe.

lonny

You can go 225/45-17 on the stock wheels. Dunlop SP9000 or Bridgestone Potenza RE730's are good choices for holding the road

JTang

Are 225/45/17 tires going to be the same ration? Meaning, I heard that you can decrease a number, increase a number, and still have your speedometer to be fairly accurate. I once changed the aspect a bit and my friend told me I was then going to be a bit off. Please advise. Thanks.

rockinTLS

You will probably be off by about 1% depending on the tire you choose (in the 225/45/17 size). The factory speedo is probably not even that accurate or consistent. Each mfr's tire for the same advertised size is actually slightly different than the next.

Your stock tire is rated at 819 revolutions per mile. Something close to that will give you the same/similar speedometer reading. For instance, most of the 225/45/17 tires run between 830 to 840 revolutions per mile or a difference of 1.02%. Since the new tire is actually 1.02% smaller, at 80 mph you might actually read 81.6 mph.

city001

quick question..

will 235/45/17 fit on our stock tl type s wheels?


G

csp33

I think 235 is way too wide... Our 17" rims are only 6.5" wide... most of the measured rim width on 215 tires are 7" already... not a mere 6.5"...

city001

well..don't that just sucked ....RECALL for 17x7!!!! on our stock rims!!!!


:protest:

G

oracion

In this forum someone posted this link for calculating tire size:

http://www.miata.net/garage/tirecalc.html

bryce11

you can go 225/50/17.

moomaster_99

You would be best to go 225/45/17...and get rid of the wimpy Michelins...they suck!! Go get some Toyos or Re730s...or S03s if you have money. 225 is going to be the widest tire you can go...as 235 is already in question on 17x7s.....plus if you go to 225/45..the tires are cheaper because it is a more common size.

city001

hmm.. aight..thanks doods...

RedLined

I seem to remember reading on the TireRack web-site that it is best to keep the overall diameter w/in 0.75 inches or 19 mm of stock. You can calculate as follows where 1 inch = 25.48mm:

((Width x (profile ratio/100)) x 2) + (wheel diameter x 25.48).

For example: ((215 x (50/100)) x2) + (17 x 25.48) = 648.16 mm or 25.438 inches

Therefore, a 225 width tire would be 10 mm (or .39 inches) larger in diameter. But is that width too large for a 6.5" wheel? I don't know.

rock

Most of the tire specs I have come across recommend at least a 7" width for 225/45 17 tire. I hope it is still safe to use on a 6.5" rim. Hopefully the manufacturers just say that for liability reasons.