Tyres Query

[Fulcrum2000]

Hi All

So I got my BPU Auto TT Supra MOT'd recently and both rear tyres are advisories for wear so I am thinking time for a new set of boots and a 4 wheel track/alignment but it has me thinking.  At the time I bought the best tyres that would fit for stopping distance so have Pirelli 235/40/18s on the front and Falken 275/40/18s on the rear.  I appreciate changing them for Sport Pilot 4's is the advice usually given and this is likely to give me the best option for grip in the spring and summer but is there any appreciable difference between sneaking a 285 on the back as oppose to the 275 and can this even be done on a Supe without camber?  The price skyrockets at 285 40 in comparison and I just don't see it making any appreciable difference in grip but I'd be interested to see if anyone has gone down this path?

[mattdavies]

There was a thread a while ago where someone went down from a 285 to a 265 or something similar and they said they enjoyed the car more. 

I am BPU @ 416bhp and run a 255/40/18 Goodyear and previously a Potenza. I do not have any significant grip issues at all, admittedly mine is an auto but it puts the power down pretty reliably in the dry and I am still confident with it in the wet. 

I believe it is also down to suspension, I run an Eibach spring with a Bilstein shock. 

[raddys]

Quality rubber over width every time 

[Scooter]

You might want to check your profiles and rolling radius. Your current 275/40/18 are quite bit higher in diameter, 285/40/18 will be even larger, create a more nose down stance.

275/35/18 gives you a more even rolling radius front and back.  

 

Like Matt I find 255's fine (I'm on 255/35/18 as these very closely match the stock 255/40/17)