Higher oil pressure with synthetic? (2010)

Not to start an oil thread, but....

With the season newly upon us, I've noticed my Commando's oil pressure is running a bit lower than usual - maybe 30 PSI in conditions where it used to be 40 PSI.

I am currently running Castrol non-synthetic 20W-50 (new rings still in the break-in period) instead of my usual Redline 20W-50 synthetic. Anybody ever found that a switch from syn to dino oil resulted in lower oil pressure?

Alternatively, maybe my oil pump needs a bit of loving. It's "scheduled" to get that next winter, which I can accelerate if need be.

Appreciate any thoughts.

Maybe think about adding a shim to the pressure release valve? Might up the ante in the low revs.

Mick

No doubt, Mick, thanks. Although the "problem," if such it is, persists at high RPMs also.

I'm curious what's changed, though. Your answer suggests you're thinking it's the pump, yes?

If its lower at all revs then its the pump, a weak pressure release spring will show in a low top pressure but normal at tickover.

Why not change back to the previous oil and see, assuming this is the only thing you have changed. It would be an interesting (and cheap) experiment to see whether there is indeed a difference.

I ran full synthetic for a while and yep I felt that cold it ran at the same psi as dino but hot the synth seemed to run about 10 psi higher pressure. I always assumed that was a good thing, at least it felt like i was getting something for the extra $.

Believe me, I'll be back on syn as soon as my rings are seated.

May try a bit of straight 50W non-syn in the meantime.

Thanks folks.

Main difference between syn and dino is syn holds viscosity better and is not affected so negatively by heat cycles. Higher oil pressure could be the result.

Thanks all. I revert to synthetic in another 500 miles and will report back.