Hi all

My new 4.2SC has come fitted with 275/40R20 tyres.

I've just done a tyre comparison as follows (Mine are the ones on the right, std on the left)



Questions as follows;

1) Is it possible to update car for difference in Tyre size without GAP IID for the CCF etc

2) How do I find out the correct pressures to use - there seems no definite conclusion from this thread

3) If tyre pressures are non-standard how does the TPMS take this into account

Many thanks

Douglas 2007 4.2SC Buckingham Blue

https://www.fullfatrr.com/forum/topic63319.html

OK - so clicked on the blue writing "What Tire pressure to run" (Awards for Numptiness kindly received)

It is suggesting 36 front and 40 rear - does that sound reasonable?

Thanks

Douglas 2007 4.2SC Buckingham Blue

https://www.fullfatrr.com/forum/topic63319.html

Rears should be around 10% more pressure than the fronts on these so start with the stock pressures of 33 front and 36 rear and work up until it gets too harsh. It's not possible to adjust the tyre size without a GAP IID or other workshop interface although on mine the nav system has a calibration option which will adjust your TRIP for DTE.
At least going down a size from stock you won't be underestimating speed. 2012 TDV8 Vogue (L322)

Thanks JayGee

Does explain why cruise at 65 felt very slow though  2007 4.2SC Buckingham Blue

https://www.fullfatrr.com/forum/topic63319.html