Guys, I'm looking for advice re tyre pressures for VF2 V8 Sportswagon. Have just fitted 20inch staggered 8.5 & 10 wheels with Pirelli Dragon 245/35 front and 275/30 rears. Tyre place suggested 40 psi all round - ride feels a little harsh, grip is good. Roads 30% city & 70% rural secondary...