I am running 40 PSI in my E rated 38 x 13.5 x 20 Nitto Ridge Grapplers, If you have an android tablet or phone the alfaOBD app has the option to adjust the tire pressure values, I have the app but Have not tried is since I adjusted mine a while back with a borrowed Autel. with the AlfaOBD You can set it from 28 PSI to 80 PSI with separate values for front and rear. I have not found where to adjust on the MM3.