yup :saint:

 

It's fine. Most ford oil pressure gauges aren't the most correct readout in the set.

 

It reads high because the oil is cold and thinker. I've had my defi gauge read almost 120psi at one point. The ford gauges are pretty spot on. The pressure gauge doesn't go high enough for cold engines. Once it warms up you most likely will never spike the needle.

Send from another galaxy.

 

I understand the oil is colder and therefore makes the pressure read higher...but it seems higher than before the oil change. Would less than 1/2 quart of extra make it read higher when cold, but be a small enough amount to read normal once it's warmed?

 

Oil capacity will not affect oil pressure unless you do one of two things.

Overfill (and by a lot) to the point that the crank whips the oil into a foam and aerates the hell out of it. If you do that, oil pressure will DROP because the pump is starving and air is compressible. Number two is under fill it to the point that you starve the pump, in which case, once again oil pressure will fall and you will starve it to death.

The oils used in modern cars are multi-viscosity oils. As they break down, their viscosity levels change, and so does your oil pressure. How much? How Little? You'd need a lab to determine that.

They are designed to have a lower viscosity when cold. Wait, you say, when its cold the pressure is higher! Indeed. Part of that is because a cold engine has tighter tolerances and thus oil flow is more restricted. Until it warms up properly oil has trouble flowing. The oil itself is also designed in most cases to flow easier when cold, and thicken when hot to provide a consistent lubrication.

 

Oil capacity will not affect oil pressure unless you do one of two things.

Overfill (and by a lot) to the point that the crank whips the oil into a foam and aerates the hell out of it. If you do that, oil pressure will DROP because the pump is starving and air is compressible. Number two is under fill it to the point that you starve the pump, in which case, once again oil pressure will fall and you will starve it to death.

The oils used in modern cars are multi-viscosity oils. As they break down, their viscosity levels change, and so does your oil pressure. How much? How Little? You'd need a lab to determine that.

They are designed to have a lower viscosity when cold. Wait, you say, when its cold the pressure is higher! Indeed. Part of that is because a cold engine has tighter tolerances and thus oil flow is more restricted. Until it warms up properly oil has trouble flowing. The oil itself is also designed in most cases to flow easier when cold, and thicken when hot to provide a consistent lubrication.

While the rest of your information above is excellent, the bolded defies my own direct experience.

This article at the KEW Engineering site is consistent with my experience, and is at direct odds with your claims bolded above. Honestly, this is the first time ever I've seen a claim that oil gets more viscous with higher temperatures; it defies basic chemistry; in terms of fluid dynamics, it would make oil pressure increase with a warming engine, not decrease (this is simple physics).

I'd recommend you read the linked article -- you'll learn more about motor oil, how viscosity is measured and rated, etc. than you probably want to know

 

So the consensus is that I'm fine? Pressures look good when warm.

 

Yes.

However, what you're taking note of signals an important caution that the "ordinary Joe" pays no attention to: Letting the motor warm up to operating temps before hammering it.

Lubrication is optimal, performing its best, when at operating temps. Pushing the motor hard when cold will stress it harder because lubrication isn't working as well, and will also cause greater wear. All leading to increased risk of failure, earlier parts replacement, and overall short motor life.

All this is even more important in a forced induction motor, where the forces and stresses under heavy load are even greater.

You've got a decent oil temp gauge... use it

 

All I know is I put 5W-30 in my car and when the oil is cold the pressure is higher that warm.

Send from another galaxy.

 

My two cents: the fact is oil has way way higher viscosity when cold. And flows a lot more easily (lower viscosity) when hot.
The multi grade oil 'tries' to compensate for this, but is only partially successful!! So even any multigrade will be thick when cold, and thin when hot. Just not as thick when cold as a single weight oil.

PS it is true synthetic oil DOES flow better when very cold.
Like in Winter in Alaska, when ordinary oil is like paste, a synthetic can still flow...

And yeah Bob the oil guy rocks.

 

My two cents: the fact is oil has way way higher viscosity when cold. And flows a lot more easily (lower viscosity) when hot.
The multi grade oil 'tries' to compensate for this, but is only partially successful!! So even any multigrade will be thick when cold, and thin when hot. Just not as thick when cold as a single weight oil.

PS it is true synthetic oil DOES flow better when very cold.
Like in Winter in Alaska, when ordinary oil is like paste, a synthetic can still flow...

And just to be clear: Flow better than a non-synthetic.

No oil, synthetic or not, flows better cold than hot (except for some exotic lubricants that don't apply here).

Further, multi-viscosity oils also thin as temperature increases. However, the rate at which overall viscosity decreases with temperature is attenuated by blending grades with different viscosity profiles.

I think this is what thirdgen was trying to say, but got stuck on the incorrect assertion that oil viscosity decreases with temperature.