Originally Posted By: quarterliter
I wanted to put a pressure gage on, but it was very complicated to do so. Am I wrong in thinking that the engine will reach its bypass oil pressure on both 30 and 40wt, just at different RPMs?
I installed a pressure gauge on MrRC45 to test that theory and I found its true...
running Mobil 1 0w30 I build 10 psi for every 1,000 rpms which is ideal whereas running
Mobil 10W40 its more like 12 to 13 psi for every 1,000 rpms which is not ideal because
the flow would be escaping the bypass sooner which means the engine would be building
pressure at the expense of flow and flow is what really lubricates our engines...
I would not recommend a straight weight oil because there is no advantage over
multigarde... hit the starter on a 104º day at the track and the straight 30wt viscosity
is 98 which too thick to flow properly... if you warm up the oil to 212ºF the straight 30
thins out to a viscosity of 10 which is ideal... I recommend Mobil 1 0W30 for it starts
up with a viscosity of 56 but matches the straight weights viscosity of 10 at 212ºF
Technically speaking a 0W30 5W30 and 10W30 30wt are essential the same
viscosity at operating temps... its just the 0W30 and the 5W30
thickens less when you turn your key off... this is real progress in
our oils because now there is less wear during start up before warmup
like Robenstein pointed out...
Oil Type......Viscosity @ 104° F....Viscosity @ 212° F
Straight 30.....................98.................10
10W-30..........................62.................10
5W-30............................56.................10
0W-30...........................56.................10
Mr.RC45 digital Oil Press Gauge
RC45 Oil System
Mobil 1 0W-30