Originally Posted by ohwell
ok so by the same token, raising them to 39 is equally unwise?
39psi is fine, because that isn't above the max cold pressure.
eg, on a std 1999 156 the minimum cold pressure was 2.2 bar for low loads up to 2.5 bar for full loads. There was also an additional 0.3bar required for constant high speed use, which took the max cold pressure to 2.8 bar (41psi).