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Discussion Starter · #1 ·
OK, so I've got a couple of bucks to do something fun. I think the OEM tires suck, and I think the OEM rims are too narrow for something significantly wider (I'm thinking 245/40/17, so an 8 or 8.5 inch width is what I really need). Has anyone besides FluXtC put really wide rims on their tC? At least 8, preferably 8.5 or even 9 would be great to know if it fits. Michelin likes the 8.5 for Pilot Sport PS2s in 245/40/17, and that tire has an almost identical rolling diameter as the 215/45/17 OEM size.
 

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Discussion Starter · #3 ·
Trucks and cars are quite different for tires. Check the recommended rim width. Minimum is 8 inches. The concept is to improve performance, not create a tire that wants to roll over the lip of the rim when I corner.
 

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Discussion Starter · #5 ·
Sure, and they'd skidpad at .8 g thinking it was awesome. I'm looking for .9+, preferably 1.0+ like my Supra.
 

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Discussion Starter · #7 ·
Thanks for the link. Anybody tried wide wheels with 17's? I've bent the OEM rims on my Supra three times, I'm not excited about 18 or 19" wheels or their increased unsprung weight.
 

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How about 225 on stock rims? I really don't want to buy aftermarket rims and I really want wider tires, at least on the front...
 

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Discussion Starter · #11 ·
255/40/17 is only 1.6% larger too, and there are LOTS of choices in that size. It's the OEM rear size for Supra TTs. Very handy for me, I have some of them laying around.
 

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I don't want my tires to do this:



Sorry for the crude drawing...

And I really want 225/45/17 - it would drop the RPMs 1.5% and add a little bit of extremely needed rubber under the car.
 

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Hey Lo bux I'm running 18x8" with 225-40-18 tires.

And they look good...and they corner excellent.
I've taken a few offramp curves at 90.
 

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Discussion Starter · #15 ·
Z, I seriously thought about 225/45/17 with the OEM rims, but as simplespirit says, it's only 10mm. Not even a half inch wider. I doubt that size will bulge out on the stock rims. Tire Rack says 7 inch is OK for that size too. To add to the width change, a compound change like the Michelin Pilot or Goodrich KD will make a huge difference. I think with those tires, you've got a pretty powerful combination for the stock rim. I'm just thinking it would be great to stick 245's or 255's under the thing because the poor car weighs a lot for its size.

Simplespirit, to your point about 17 x 8's, since we have a McPherson front end, I am concerned about the rim hitting the strut tube. I don't like changing the offset to accomodate clearance issues because it changes the loading on the wheel bearing. A wider rim might clear on 18's and 19's but not on 17's. I am totally with you, I'd like 17 x 8 or 17 x 9 wheels to give me maximum flexibility for wider rubber.

I plan on all four corners being identical too, any text you read on setting up your car starts with, "it's best to have all four tires the same size." I also have a number of friends who spend a lot of time at track days with their Supras. I've heard them all say the ideal set up for a Supra is 315's all the way around. Assymetric sizes look cool, but I'm a function over form guy.
 

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Did couple of searches - still can't find the recommended rim width for the tire width, but found one interesting post on some forum. Basically the guy says that simply putting wider rubber on the same rim might not result in bigger contact patch.

QUOTE
a 225 on a 8" rim will put 8.7"s of tread on the ground
a 235 on a 8" rim will put 8.6"s of tread on the ground
a 245 on a 8.5" rim will put 9"s of tread on the ground.[/b]
So maybe we are making things worse?
 

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Discussion Starter · #18 ·
That's why I use the spec chart at the Tire Rack site. They have the recommended rim width for every tire they sell. The recommendations come from the tire manufacturers. If you can't believe them, who can you believe?

The other thing about the actual rubber on the ground is the numbers will be very tire model specific. There are more variables than rim width affecting the contact patch size. My bet is if you play with inflation pressures you could probably get them all to have the same contact patch within a couple of percent....
 

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Did a lot of reading on TireRack, looked at the specs. 225 might be ok for the most part.

While I was there I looked up Potenza RE92 ratings - is it true that we have the worst tires on Earth? They do feel way less sticky than Falken Ziex that I had on my Matrix, but they cost 2x as much as Falkens did... Maybe all I need is better tires, and I can live on 215.
 
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