19"Rims
 

I currently have the following rim / tyre sizes:

Front 235 x 35 x 19 inch
Rear 275 x 30 x 19 inch

I'm wanting to increase the size of tyre a little and as I'm ordering from Tire rack importing back into Australia I'd appreciate what you guys think about the following combo:

Front 245 x 35 x 19 inch
Rear 295 x 30 x 19 inch

From the Tire Bible the circumference difference is less than 2% so that shouldn't be an issue, and the tires appear to fit the 8 inch front and 10 inch rear rims.

Tyre choice will be Michelin Pilot Super sports - Have them on my Evo and they are nothing less than excellent.

What I'm trying to do is to fill the wheel arches a little more with any appreciable change to handling of the car.

In layman terms I would have thought more tread on the road, the better the handing would by anyway.

I have 15mm from the edge of the rim to the wheel guard on the front so I'm thinking there wouldn't be an issue with the tyre sticking outside the guard.

The rear is only 10mm so I'm guessing I'll be on the limit.

I realize each tyre type has a different shoulder width, which may impact on the above.

As I'm importing I'd like a bit of feedback first.

Welcome any comments / recommendations

Cheers

Well I do agree that the more tread on the road the better the handling but if this is on a boxster I would really think the 245's up front would rub when cornering hard. Porsche does a very good job with picking sizes for the cars max performance though. If you go too wide even if you're not rubbing side walls you're gonna be loosing acceleration. I'm not sure how hard you push your boxster but even though it does a great job of not leaning much in corners it will lean so I'm pretty sure those 295's will cause some problems in the rear. Just a guess though, could work wonders but personally I wouldn't chance it.

I just checked for your speedometer reading currently with what you have at 60 mph yours will show 58.9 and with the 295s it will show 57.8.
So remember if you're driving in a 75 mph zone and planing on speeding then you'll be going quite a bit faster then you think which cops would love to screw up your insurance by giving you a ticket for.

Your current fitment is already extremely aggressive . You're right at the very limit in terms of what will fit on a 986 boxster . I can't imagine that you'll be able to fit a 295 on the rear.