change to thinner oil = less oil pressure??

[Foxfan88]

i was using 20w50 about a week ago and now i am running 10w40 and now my oil pressure is lower, is this normal??

 

[Insane3D]

Thinner oil will be easier to pump, hence lower pressure. This is why your oil pressure starts high, and then drops a bit once it heats up to operating temps and thins out...

How much lower is it dropping?

 

[Foxfan88]

well think of the stock guage as 4 marks

it used to be around the 3/4 mark now its closer to the 1/2 mark

 

[HISSIN50]

Think of it this way. Pressure (as read on your gauge) is a measure of the resistance to flow. Molasses would give awesome pressure (very resistive to flowing), but also provides little lubrication.

As I often post, I would go with the oil that gives you decent pressure in all operating conditions (real hot idle is probably where one would see the least pressure).

But yeah, I run both those viscosities and I notice the 10W-40 runs 5-8 PSI lower at hot idle (than 20W-50). My stock gauge would not know the difference.

Good luck bud.