Tire width?

[LAP1DOUG]

Tire widths are not very uniform. That is some manufacturer's "275" may be closer to being a "285" or visa-versa. The bast way before you purchase is to compare data from TireRack.com, or from the tire manufacturer's site.

That said, on my 986S, I am running 285 rears with Hoosier A6's, which generally run quite wide. These are a 11.5" section width when mounted on a 10" wide wheel. I have not rolled my fenders at all and this works, but if I was lowered a bit more there would probably be some contact.

So, running a 285 is possible, but it depends on wheel offset, ride height, and suspension stiffness (max wheel movement).

Take careful measurements.

[woodsman]

Too much tire makes a car feel numb and heavier. I think this is one of those places where 'more is less'. I bought the stickest tire I was willing to pay for, in the stock size. Also, overall diameter affects ABS, PSM and overall gearing-if you change the FR/RR stagger you may trigger these devices. Bigger tires slow you down except when at steady state max cornering speeds-because they're heavier. Even on the street ( and that is what I'm talking about), I think tire/wheel weight matters more than trying to get every last 'G', especially on a Boxster which is engineered for agility and steady-state cornering.
Next year I'll be going ultra-light with 18 and 20LB wheels and 225/265(or 255) tires. My car will be more responsive and will react to bumps- from minute to large) better. It will also feel like it's overall weight has been reduced and it will accelerate and brake better. What's not to love? Sometimes bigger looks better though- to each his own.

[BYprodriver]

Originally Posted by woodsman

Too much tire makes a car feel numb and heavier. I think this is one of those places where 'more is less'. I bought the stickest tire I was willing to pay for, in the stock size. Also, overall diameter affects ABS, PSM and overall gearing-if you change the FR/RR stagger you may trigger these devices. Bigger tires slow you down except when at steady state max cornering speeds-because they're heavier. Even on the street ( and that is what I'm talking about), I think tire/wheel weight matters more than trying to get every last 'G', especially on a Boxster which is engineered for agility and steady-state cornering.
Next year I'll be going ultra-light with 18 and 20LB wheels and 225/265(or 255) tires. My car will be more responsive and will react to bumps- from minute to large) better. It will also feel like it's overall weight has been reduced and it will accelerate and brake better. What's not to love? Sometimes bigger looks better though- to each his own.

My thoughts about street driving exactly. My car is much more nimble & fun to drive on stock 17" tires. If CarreraII wheels were made in 17" that's what I would have on my car.