Hello everyone, I have been reading the board for sometime and have been learning a lot of great information. I now have a couple of questions on which you might be able to help me. I live in the UK and drive a 1976 Bristol 603. This is an obscure British car which uses a 360ci Chrysler engine. The old engine has just been replaced with a new 360ci Mopar Magnum engine (300hp and 375lbft) which now has about 1000m on it. The oil was changed shortly after first start up and again after 200m. It is currently running 20W50 dino until about 2000m. The idle oil pressure on cold (ambient of say 15oC) start up is very high, i.e. 90psi. When the engine is good and hot the idle oil pressure is about 45psi and the non-idle (>1000rpm) pressure is 80psi. The mechanic who fitted the engine, which is built by Cummins for Chrysler, said they are built with tight clearances and the engine would need a little time to loosen up. It certainly does feel to be getting quicker which more miles on it. Questions: Should I be worried that these high oil pressures might indicate I'm not getting enough oil flow? If the engine is built with tight tolerances, then would a lower viscosity oil (e.g. 0W30 synthetic) be a good idea when the 20W50 comes out at 2000m so as to get the flow rate up? Thanks for you help. PS - I have found a UOA lab in the UK at approx $10 per sample, but have yet to try them.