[tom s]

Did I miss somewhere what weight oil is being used?Tom

[Schurkey]

Originally Posted by gto4evr

it floated around 20 psi at idle and 60 under a load...

...80 under a load.

Originally Posted by gto4evr

the old top out of 60 psi under a load once warm?
...everything reacts the same under a load

There's nothing in the engine oil system that measures load. An automatic transmission might vary line pressure based on engine vacuum or throttle position, but there's nothing like that in the engine oil system.

Originally Posted by tom s

Did I miss somewhere what weight oil is being used?

Important.

[gto4evr]

Originally Posted by Schurkey

There's nothing in the engine oil system that measures load. An automatic transmission might vary line pressure based on engine vacuum or throttle position, but there's nothing like that in the engine oil system.


Important.

I should have been clearer. by load I mean the oil pressure at high rpms.

in the past, I'd get 20 psi at idle and 60 at high rpm with a hot motor. cold engine was basically +20 to both numbers and hot, it would be 20/60. Now I'm getting 40/60 with hot conditions and 40/80 with cold condition.

so is it possible my memory's shot and somehow I did do an oil change at some point last year and used the synthetic blend, and that's what's caused the oil pressure change and I just didn't notice it? does blended synthetic oil increase psi? I just can't see that, every time I do an oil change I write down the mileage and date on the filter box flap, and jam it behind the air line pipe over the door on my garage and I have every oil change for each car I own as a history of flaps. The flap previous to this change was dated 2017 and 900 miles less than the change I just did.

another piece of info if it matters, filters are the napa gold 1258

[68WarDog]

Originally Posted by tom s

Did I miss somewhere what weight oil is being used?Tom

This^^^

[gto4evr]

sorry, I hate leaving details out!

10W30 oil. synthetic/blend after the oil change, had regular 10w30 in it before the oil change test. there was no oil change between the 2020 20psi idle and the 2021 40 psi idle.

it's had regular 10w30 since day one. has 5000 miles on it since the rebuild in 07