I am sure this could be posted in the TireRack Section but I figured I would break the rules

I know we have been talking about the limited supply of 20"s tires such as Michelins and Pirelli's in the 325/25/20.

Hankook K107 and Dunlop Sport Maxx GT has 325/25/20's but not in the US Market.

We also know that sizes can vary from on tire manufacturer over the other. But when it comes to less than a 3% variance is what we concerns ourselves in regards to the 997 AWD Turbo's right?

For Example:

Advan Sport makes a 305/25/20 but that seems to be the size that people don't want with a 245/30/20 combo.

But if you look at some of the technical specs it is almost the same. Except for width which isn't the problem.

Michelin 325/25/20 = 12.9(width) | Advan = 12.2(width)

Michelin 325/25/20 = 26.4(Diameter) | Advan = 26.1(Diameter)

Michelin 325/25/20 = 789(Revs per mile) | Advan = 797(Revs. per Miles)

Michelin 245/30/20 = 9.8(width) | Advan = 9.6(width)

Michelin 245/30/20 = 25.8(Diameter) | Advan = 25.9(Diameter)

Michelin 245/30/20 = 805(Revs. P/Mile) | Advan = 802(Revs. P/Mile)


OEM Specs:

235/35/19 and 305/30/19

Michelins 235/35/19 = 9.5(width)

Michelins 235/35/19 = 25.5(Diameter)

Michelins 235/35/19 = 817 (Revs P/Mile)

305/30/19

Michelins 305/30/19 = 12.3(width)

Michelins 305/30/19 = 26.25(Diameter)

Michelins 305/30/19 = 788 (Revs. P/Mile)


With that data couldn't we use an Advan Sport 305/25/20 instead of a 325/25/20?

It doesn't seem to be over a 3% variance.

I had some time on my hands today as well as looking ahead for new tires with the shortage of Michelins in the 325/25/20 size. I like the Advan Sport as well as the Sport Maxx GT(read great reviews of it that preferred them over Michelins - Also Cargraphics use these tires on the GT3 they modded in 19's and said they perform better than Michelins)


Any thoughts?

 

What about the new Michelin CUP tires 315 25 20 ?