New Tires
Melting Slicks
Joined: Sep 2021
Posts: 2,555
Likes: 1,213
Something is off with your numbers. A 275 should be 275mm tread width, a 285 should be 10mm wider. And since the aspect ratio is a function of tread diameter a wider tread with the same aspect ratio should result it a taller tire. Your data has the diameter the same.
If I were to guess I'd say converting from metric to inches and back is probably introducing errors somewhere.
If I were to guess I'd say converting from metric to inches and back is probably introducing errors somewhere.
Burning Brakes
Joined: Jun 2015
Posts: 1,157
Likes: 522
From: Central Jersey
Something is off with your numbers. A 275 should be 275mm tread width, a 285 should be 10mm wider. And since the aspect ratio is a function of tread diameter a wider tread with the same aspect ratio should result it a taller tire. Your data has the diameter the same.
If I were to guess I'd say converting from metric to inches and back is probably introducing errors somewhere.
If I were to guess I'd say converting from metric to inches and back is probably introducing errors somewhere.
Just checked Michelin website and the 285/30R20 OEM pilot supersport is listed with 26.8 diameter while the 275/30R20 4s is still listed as 26.5. So the math now works but the difference is very slight and not really significant.
Last edited by blueray16; Feb 10, 2024 at 11:00 PM.
