While I was aware the new cars have a variable pressure oil pump I was not aware...

Minus 40 degrees... Is that Fahrenheit or Celsius?

the pump ran when the engine was off. I was under the impression the oil pump was driven by the engine, not by some electric motor. I wonder if there is some supplemental electric oil pump motor though?

I have not spent any time in one of the newer cars the ones with the variable pressure oil pump so I haven't experienced this for myself but the techs told me about that variable pressure setup that it was at first strange to rev the engine and see the oil pressure climb but if one held the rpms at an elevated but constant level the oil pressure would drop down from say around 4 bar to just 2 bar because the engine at that load/rpm/temp/etc that was all the oil pressure that it needed.

Sincerely,

MarcW.

[www.faqs.org]

Minus 40 degrees... Is that Fahrenheit or Celsius?

It's been this way for a few years now. All the 9A1 engines have the electric oil pump. Reduces the power draw on the engine. There is no redundant motor for the pump.

Minus 40 degrees... Is that Fahrenheit or Celsius?

Apparently essential for oil return to the sump during hard braking and cornering, maybe acceleration, too.

Minus 40 degrees... Is that Fahrenheit or Celsius?