User 92421

With is still way up for debate, so it's basically about aesthetic appeal until there is concrete research findings.

jc5057

I ran 275 s on the rear then went wider 305 night and day diffrence 305 hooks up way more they come stock on the gt 350 for a reason more HP wider to put the power to the ground

Norm Peterson

The more important thing about the GT350's tires is that they feature grippier compounds. The extra width is mostly for improving things like cornering stiffness, turn-in response, steering precision, and durability under really hard running. Any benefit to acceleration is almost incidental.


As long as the tire size is appropriate for the car's weight, sticky (by itself) is better than wide. Wide without sticky nearly always promises more than it can deliver ( <cough> NT555 <cough> ).




Norm

barstowpo

With all other factors being equal, a larger (wider) contact patch has to offer increased grip over a smaller one. The exception would be in low traction environments like snow, ice or perhaps even wet.

User 92421

Except that as width increases, the pressure exerted across the tire decreases as the cars weight spreads across a now wider plane. I know, it sounds odd. It's been studied see here : http://www.autocross.us/forums/topic...-narrow-tires/

barstowpo

OK from that last paragraph in the first post, it would appear wider is better due to the irregular surface of the pavement.

User 92421

Typically on dry asphalt, yes wider is better, but on wet pavement or most anything else not so good.

barstowpo

I would completely agree with that. My car gets quite squirrely in the wet especially if its cold.

Norm Peterson

I haven't read that entire linked thread, but I suspect that even it isn't going to get into the matter of unit load distribution over the contact patch area. Every discussion I've seen throws corner weight over inflation psi and calls it done. It's not. Tire structure has finite stiffness, which causes the actual psi between any particular little area of the tire tread and the ground to vary depending on where in the contact patch it is. A variation approaching 2 to 1 is entirely possible. Tire pressure tuning works with this effect (and others).





Norm

User 92421

excellent point, tire psi tuning is a great way to get the most out of a tire at the track, as for street driving it becomes quite impractical.