HI I have a 612 and have recently fitted new wheels / tyres Can you help with the tyre pressue please Perellis Front 245/35ZR20 (95Y) Rear 305/35 ZR20 (104Y) thanks
Those are not standard 612 rear size tires (285/35 20 OEM), so the closest in the 2009 OM is 33 F, 30 R. With the larger rear tires, I would try 33 psi F&R and see what that does for you. All the tire pressures Ferrari recommends are developed empirically by a test driver, so in this case, that is you. Adjust accordingly if you do not like the feel with 33/33 as a baseline.
I run mine with a higher pressure in the front versus the rear, about 10% difference. I believe that's per Ferrari recommendation and seems to work well although I am on standard 612 challenge wheels with MPSS. As an aside I saw my rear tyres get up to 60c whilst on our Italian road trip!