dubbleugly01

iTrader: (24)

Reading some of the threads on this subject, I find it amazing the oil pressure is so low at idle (4.2 psi) from the factory. I just installed an oil pressure gauge, tapped into a passage on the head that has been recommended here in several threads.

My question is, does anyone change oil weights to get a desired oil pressure reading? For instance, my oil pressure is around 50 psi above 4000 rpm when driving hard. Which (I think) is on the lower end of acceptability. If I went with a 10W40, it should bring the pressure up some. Just wondering if anyone is doing this.

The service manual states 42 psi to 100 psi at 3500 rpm is acceptable. Recognizing tolerences on a prodcution based engine will vary, maybe that's why there is such a large range on acceptable oil pressure? With all the spun bearings that keep getting posted about, just wondering if going to a heavier oil and getting the pressure up would be a step in the right direction for engine longevity.

As a side note, just installed the 3 gauge pod from Gruppe-S that relocates the radio. Awesome setup, fit and finish are both top notch

mooreboost

iTrader: (6)

Im currently running 15w-50 and Im at 90 psi at crusing.

After talking around I think Im going to go back to 10w-30, as Im afraid the higher pressures will cause increased wear on the seals in the head.

dubbleugly01

iTrader: (24)

Any idea what your oil pressure was running on 10W30 at cruise? I might try 10W40 for a day just to get another data point, unless someone has already done it.

fsugatorbait

iTrader: (16)

I see ~80psi at 3200 rpms in 5th.

dubbleugly01

iTrader: (24)

Is that on 10W30?

EVOONYOASS

iTrader: (2)

Is synthetic 5W30 ok?

fsugatorbait

iTrader: (16)

Yes. Mobil 1.

dubbleugly01

iTrader: (24)

for what it's worth, I just put in Mobil 1 10w40 and ran the car till warm. I may have picked up 5 psi at anything above idle, and only about 2#'s at idle.

So on my car, 10w30 idle oil pressure is around 5#'s (Defi BL gauge) and 45#'s at 3500 rpms, and about 50#'s while driving above 3500 rpms. 10w40 had an idle pressure of about 7#'s, and 49#'s at 3500 rpms and around 55#'s while driving above 3500 rpms.

Not much of a difference.

nothere

iTrader: (23)

remember, more pressure is an indication of how hard it is for the oil to be moved through the bearings. thin oil would move easier, thick harder, which one do you really want? so low pressure may be a good thing, as long as oil is being pumped.

jrsimon27

iTrader: (1)

has anyone tried mobil1 0w-30?? is it ok to use it?? a friend told me to use it cause it gives more protection at startups then 10w-30 and it gives the same protection when warmed up??

Andrew LB

I've wondered the exact same thing. Most of the Audi/VW guys I worked on cars and raced with used 0w30 or 0w40 here in Southern California.


I do know some Evo guys who run 15w50 on hot track days. But not for daily driving use.

HiVoltEVO8

iTrader: (4)

Nothere is correct. Flow is far more important than pressure. All of the chevy SB guys used to make this mistake also. If you raise the viscosity, you actually are reducing the flow and robbing more horsepower to run the pump. It may seem insignificant, but oil pumps, at high-pressure, can take as much as 15-20 Hp to operate at high rpm.

HiVoltEVO8