New Tires on Stock Rims: 215 or 225?
 

Have about 22k miles on the car and the stock tires are toast. I'm pretty much decided on the Michelin Pilot Super Sports (unless someone can talk me out of them), just trying to decide between sticking with the stock 215/45R17 size or going up to 225/45R17? Any compelling reason to go one way or the other? Car is stock except for an OFT, and I plan to keep it this way at least through this next set of tires.

Unless you track it, I would stick with 215

Read the tire specs on stock tires and the mpss. Look at overall diameter and recommended wheel width.
I would choose whatever is closer in diameter or slightly bigger than stock. Those tires have a good compound so any size would be an upgrade in grip.

Stick with the factory 215 width unless you want a more expensive, heavier, and less responsive steering but the same grip tire in a 225... if it were an 8" wide rim it would be a different matter and the 225 width would probably be more preferable with it's 8.2" tread width. Also, the 225/45-17 size will have your speedometer off on the high side, meaning you will actually be going faster than what the speedometer shows (by a few MPH at Hwy speed) and your acceleration will be a little bit slower...

Personally I would go with a different size MPSS though for even better performance improvements over the stock tire size... 205/45-17.

Stock size. I run stock size using Dunlap Star Spec Z2. I'm turbo'd. No traction problems unless if I turn the wheel and gun it. I see no reason for me to move up to a wider tire. I don't track the car. It's just my DD.

Hmm, hadn't considered going to a smaller tire. Why would you recommend going a size smaller? Keep in mind this is just my DD with a lot of time spent at 70+ mph and no track time currently.

The 205's are $44 more expensive than the 215's on TireRack. I'd stick with the stock size for that sort of price differential.

I'm on the TRD rims from yota. 215 40 18 front on a 7" rim and 225 40 18 on a 7.5 rim rear. Works great and the handling is to my liking.


If you have the stock wheels stick with the stock tire size and the Super sports are an awesome tire.

215 super sports are going to be noticeably wider than the stock primacies in the same size, so I'd definitely stick with 215's. My 205 snows are wider than the 215 primacies, and my 225 RS3's are much wider (way more than the 10mm you'd expect).

Imma thread jack this for a moment. How do you guys think stock sized MPSS would fit on a 7.5" wheel?

I don't see a problem at all. I run Dunlap ZII 215 on my 17x8 wheels with no issues. It has very little stretch.

I just installed 215 PSS on stock rims. Was considering 225's as there was a new unused set for sale privately but the seller was trying to play on my ignorance and sell for more than new from a dealer. Made a call and ended up with 215's as recommended and paid less with tax, warranty and install than resale for the new 225's uninstalled. Just tried them tonight after swapping wheels in my garage. They handle better in wet than the stock Primacys do in dry. However, I am glad I used the stock tires for 33000 kms to better learn how the car handles at lower traction limits. For most drivers the Primacys are fine. I am planning to do some track driving this year.

Tread width on 215 OEM primacy's is 705" at 20 lbs Per Tirerack.com

Tread width on 215-45 MPSS is 7.7" at 20.5 lbs. per Michelin

Tread width on 225 MPSS is 8.2" at 22.8 lbs. per Michelin

Corrected, due to looking at the wrong column in my spreadsheet, where I have been comparing tires and various wheel options. Apologies.

Everyone should learn on the primacies, they're great for being communicative and progressive. I'd suggest everyone does their first couple track days on them too to better feel out the car, but the PSS will definitely be good too.

Have you decided on any days yet? SPDA has a day in late May (23rd) on the CTMP DDT that is perfect for people getting their feet wet (with on site coaching for all beginners and anyone else that wants some tips).

What are those weights based on? Including the wheel? Which wheel? A 215/45/17 MPSS is 21lbs and a stock Primacy is 21lbs (both according to tire rack).