Need some advice on tires

[wparsons]

Unless you're trying to purposely soften the responses of the tire, you generally want the widest rims recommended for the tires. The less bulge there is the sharper the turn in will be and the more you'll feel feedback from the tires.

A measurement more important than the advertised width (ie 225mm) is the actual tread width. A 215/45/17 Primacy HP has 7.5" of tread, while a 215/45/17 Dunlop Z2 has 8" of tread. They have the same section widths (8.4") and rim range (7-8"), but if you look at the two beside each other the difference is quite obvious.

You're far better off all around by buying a better compound in a narrower width than a wider tire in a worse compound. If you're just driving on the street, 225's in a good sticky tire are plenty of grip.

245/40's on an 8" rim will be fine, but for my money I would go 225/45 (which I did).

[djliquidsteele]

Originally Posted by Touge86

But is doable necessarily better? I still can't figure out if 245/40 is simply the better pick overall. (would it look awkward on the rim? better for handling/performance?)

Check my build thread to see what it looks like. 245/40 is going to look exactly like what I have. I have Michelin PSS.

As for performance, if your looking to still be able to get the back end out, go narrow. If you're looking for stick, go with the 245/40. Plus I think the 245/40 looks better.

Just my 2 cents.

[wparsons]

245/40 PSS's are about $200/tire, or roughly $50/tire more than 225/45 PSS's. IMO it's not worth the extra cost for the wider size in that tire. If you want more grip, get a 225 width RS3, Z2 or Rival. If you REALLY want to stick, get 245/40 RS3's for about $150/tire.

Also, a 245/40 PSS only has 0.3" more tread width than the 225/45 PSS (8.5" vs 8.2"), where the 245/40 in other tires have 9.2"-9.5". A 225/45 Rival has 8.5" of tread, so it's the same footprint as a 245/40 PSS.

I'm not saying the PSS are bad tires at all, but if your first concern is grip they're far from the top of the list.

[ZDan]

Originally Posted by wparsons

I'm not saying the PSS are bad tires at all, but if your first concern is grip they're far from the top of the list.

Under track conditions, maybe. In real-world street conditions, the PSS gives little/nothing away to Extreme Perf category tires in terms of grip, and is clearly superior in wet grip.
http://media.caranddriver.com/files/...res-tested.pdf

That test doesn't include the new Direzza ZII or RE11A or BFG Rival, but still, besting the RS-3 in dry autoX is no small accomplishment for a more balanced real-world street tire.