Pennzoil Platinum VS Quaker State Ultimate

[RicD]

I never understood why folks say use heavier weight oil in hot weather; does not make a lick of sense. Besides lubricating, engine oil is to cool the engine.

Oil flowing faster, the more it cools; a thermal dynamics thingy-bob. Heavier weight oil does not flow as well, cannot dissipate heat as well as lighter weight oil such as 20 weight oil, thus heavier weight oil does not cool nor lubricate as well. In hot weather to help cool the engine we need more oil flow, not less oil flow.

Regardless of the ambient temperature, 0 degrees or 100 degrees, the fully warmed engine is at the 200-ish temp. Thus when ambient air is hot why use thicker oil, the engine is not effected by that ambient temperature; remember it is operating within itself at the 200 degree range?

Living in Metro Atlanta we have horrible commute traffic, gridlock stop and go. This year we had 90 day of 90 degrees or more; one day short of a record. My cars contain either 0w-20 or 5w-20 oil. Also, during the hot summer on long 70 MPH road trips it contains the same oil. On a run out to Oregon and back same oil.

If the engine temperature gauge starts climbing out of normal range we need more oil flow to help cool it. We also should have our cooling system checked as well. It could have plugged radiator fins, thermostat not performing properly, radiator fan not kicking in as it should, any number of things. Putting in heavier weight oil for hot weather is not an option

My DD is a 2004 Xterra, oil capacity is 3.5 quarts of oil, including the filter.

 

[Robenstein]

Well the engineers that make the engines and print the manuals often have recommended heavier oil in hot climates. Indeed sometimes thicker oil can cool better, especially in air cooled motors. I know in hot parts of the world the same 2AZ-FE engine has in the manual stating in hot weather that 40 and 50 weight oils are recommended, while here in the states it is speced for 5w20 or 5w30.

 

[ottotheclown]

I find it hard now to get these spec. thanks , also the VI is better in the Quaker State Ultimate Durability for the price it always is the best choice. In addition in the 5-20 flavor Blackstone listed a TBN of 9.2. That is near the EP oils like Mobil.

 

[volk06]

PP has a bit more boron that Quaker State Ultimate Durability if I remember right.

 

[RicD]

Robenstein, thank you for your comment.

Yes, air cooled engines I could understand thicker oil, but not in a water cooled engine. Air cooled engine temperature fluctuates all over the range. Water cooled should not vary 10-15 degrees of the thermostat. If it does something else is in error.

Lighter oil flows faster, removes more heat, thus cooling better than heavier oil. An engine in slow stop and go traffic during hot humid weather needs all the cooling it can get. Much cooling comes from the water jacket much comes from the oil. Thick oil builds up resistance thus causing more heat, and being as it does not flow as fast it does not dissipate heat as well as lighter oil. Flow effects cooling not thickness.

Be aware our engines cooling system cannot tolerate much over 230, our oil can. It is the cooling system that is an issue not the oil.

A final thought: regardless of oil used make sure it can produce 10 PSI per 1,000 RPM. Thus, if we are getting 30 or 40 PSI at 2,000 RPM our oil is much too thick. If memory serves me well, Formula 1 cars run maybe 5 or 10 weight oil; they are turning serious RPM.

 

[Robenstein]

I get 30 psi of oil pressure on a stock chevy small block 305 with 10w30 at 1,000 rpm and my mothers Blazer with a 4.3 Vortec gets 40psi at startup with 5w30 when its 60 degrees out and stays that all the time.

 

[lexus114]

Originally Posted By: Robenstein
I get 30 psi of oil pressure on a stock chevy small block 305 with 10w30 at 1,000 rpm and my mothers Blazer with a 4.3 Vortec gets 40psi at startup with 5w30 when its 60 degrees out and stays that all the time.



factory dummy gauges are so precise.

 

[Garak]

Originally Posted By: RicD
Lighter oil flows faster, removes more heat, thus cooling better than heavier oil. An engine in slow stop and go traffic during hot humid weather needs all the cooling it can get.


Agreed. A lot of the thicker is better thought is outdated, but there are still some valid points. If a vehicle gets the sump temperatures very high, an oil that starts thicker will generally stay thicker, and the concern is that something too thin will thin out unacceptably. Of course, that can be checked with oil pressure and oil temperature gauges, assuming one knows the expected specifications.

Some vehicles do better with thicker oil. Some do not. My old Audi 200 Turbo called for very thick oils over most temperatures, and would consume 30 weights. Yet, it's sump temperatures never got over 100 C - it had a huge oil cooler. With the oil temperature gauge (it was accurate; I tested the calibration myself), thicker oils always ran hotter.

On the other side of the coin, the G37 apparently runs the oil fairly warm. Guys who drive the G37s and 370Zs hard often want to put in thicker oil. Well, the things go into limp mode if the oil gets too hot. The thicker oil is going to run hotter in the first place, so that just guarantees them a trip into limp mode that much faster.

For oil temperatures, even in a water cooled engine, you're going to see wide, wide ranges. Any oil, even 0w-20, is too thick at startup and very short trips. In the Audi, at proper coolant operating temperature, I saw oil temperatures from around 50 C to 65 C (normal, light driving, such as a mixed highway/city trip) to around 80 C (hot day, very extended city driving or a 60 mph, lengthy highway run), to 95 C (100 mph with high boost for thirty minutes with high ambient temperatures).

 

[Robenstein]

Originally Posted By: lexus114
Originally Posted By: Robenstein
I get 30 psi of oil pressure on a stock chevy small block 305 with 10w30 at 1,000 rpm and my mothers Blazer with a 4.3 Vortec gets 40psi at startup with 5w30 when its 60 degrees out and stays that all the time.



factory dummy gauges are so precise.


Except I have checked it with a manual guage as well. The engine was partially sludged up when I got it and had sort of low oil pressure. After cleaning it out with some HDEO flushes and a new PCV valve my pressure started climbing. My factory gauge is within 5 pounds.

 

[lexus114]

Originally Posted By: Robenstein
Originally Posted By: lexus114
Originally Posted By: Robenstein
I get 30 psi of oil pressure on a stock chevy small block 305 with 10w30 at 1,000 rpm and my mothers Blazer with a 4.3 Vortec gets 40psi at startup with 5w30 when its 60 degrees out and stays that all the time.



factory dummy gauges are so precise.


Except I have checked it with a manual guage as well. The engine was partially sludged up when I got it and had sort of low oil pressure. After cleaning it out with some HDEO flushes and a new PCV valve my pressure started climbing. My factory gauge is within 5 pounds.



Smart man! Glad to hear that you double checked it. I do believe that some factory gauges are more right on than others. And still prefer them over idiot lights. I remember my 75 Ford Granada had a Red engine light, (not an amber check engine light) this car was before all of that. Any way, if that thing lit up, it was either low oil pressure, or an overheating problem. They just used this light for both problems.

 

[chainblu]

Originally Posted By: RicD

A final thought: regardless of oil used make sure it can produce 10 PSI per 1,000 RPM. Thus, if we are getting 30 or 40 PSI at 2,000 RPM our oil is much too thick.


I'm not sure that line of thinking (10 psi per 1000 rpm) was meant to be so precise. I've always considered my MAX rpm and then made sure my oil system was up to the task. For example, if I wanted to wind up my engine to 7000 rpm, then I'd want to be running 70 psi. If that meant by 3000 rpm I was already at 70 psi, so be it.

To be truly rpm specific would probably take a complicated pressure relief management system.

And to be honest, if I was cruising down the highway doing 70 and turning 2000 rpm. If I looked down at my oil pressure and saw 20 psi, my hair would stand straight up.