Yup, I understand that, just seems a bit riskier with an engine, which sees a different type of load than a trans. There have been a few different approaches taken with traditional PD pumps to provide variable displacement by other marques (Toyota, VW...etc) which seem less "risky". Guess we'll see how this ages.
On one episode they used 87 , 90 something, 106 Racing gas, and E 85.
They adjusted the timing for the best power with each.
Their conclusion was if a engine was tuned for max power, which in the case of the gasolines turned out to be 29 degrees all in, upping the octane then trying to advance the timing did not actually result in more horsepower.
The E85 turned out to make the most horsepower and responded to more advance. Rather than me going further with that, check out the episode.
Engine Masters used to be its own magazine altogether
The oiling system incorporates a new variable displacement two-stage vane-type oil pump that enables more efficient oil delivery, based on the engine’s operating conditions. Its dual-pressure control enables operation at a very efficient oil pressure at lower rpm, and then delivers higher pressure at higher engine speeds.
A 40wt at operating temps is multiple times thinner than even a cold 0w20. GM may recommend a thinner oil for cold temps to reduce any pressure bypass when cold, but I doubt once at temp the viscosity makes any difference to actual pump operation. Do you happen to have any exploded pics of the pump to show the vanes?
All 3.6 Pentastar V6’s are like that, 3,500rpm is where the oil pump switches to high pressure. Compared to a “normal” pump that’s sitting at 50-60psi all the time it’ll save a few fractions of a mpg.
So it looks like the main part is still positive displacement; the vanes simply are a controllable “pressure relief” that directs oil to the engine or back to the sump, yes? That would mean it’s essentially the same as ever, it’s just a computer-controlled “leak” rather than controlled by a spring. At least that’s what it looks like.
Yes, it sounds the same as the Pentastar (described above), but I'd like to see an exploded view, like Subi.
That's a normal PD pump you are showing there, FYI.
I don't think that's the right pump, that looks like a normal PD pump. See the pic of the Pentastar pump, that's a vane pump.So it looks like the main part is still positive displacement; the vanes simply are a controllable “pressure relief” that directs oil to the engine or back to the sump, yes? That would mean it’s essentially the same as ever, it’s just a computer-controlled “leak” rather than controlled by a spring. At least that’s what it looks like.
I see now how the vane pump works. The center ring is on an eccentric, and moves to decrease or increase the vane length. Completely different than what I was thinking; I had a VGT-style image in my head where if the vanes were open, that was bypass. When fully “shut” which would correlate to low-speed on the turbo, that would be sending all the oil into the engine. Thanks Overkill, much appreciated!
You are quite welcome.
I think people on the board have even used 40wts in the Pentastars? Operating temp should be the overriding equalizer on vane style pumps from how it appears, especially if it’s using sensors to control pressure.
I ran 0w40 in my 2016 v6 300, engine didn’t seem to care other than the base oil pressure rose from 30 to 40psi.
