HandOverFist
Rich
Quaker State has recently introduced a new conventional oil with impressive credentials that rival synthetic's. From 540Rat's test chart...
"19. 10W40 Quaker State All Mileage, API SP, conventional = 126,055 psi
This is BY FAR THE BEST performing “CONVENTIONAL” motor oil I have ever tested.
This IMPRESSIVE (for a conventional motor oil) psi value is NOT an outlier value. I test every oil several times, then average all those values to arrive at the most accurate and representative value, that I post. This oil tested rather consistently, and none of its test values was very far off from this posted average. This is simply an excellent performing conventional motor oil.
This motor oil contains “seal swell/seal conditioners”. It was tested in Spring 2023.
zinc = TBD
phos = TBD
moly = TBD
The psi value of this new oil, came from testing it at the normal operating test temperature of 230*F. I went on to also test this oil at the much higher temperature of 275*F. At that elevated temperature, most hotter and thinner oils typically experience a drop in Wear Protection Capability. At that elevated temperature, this oil produced 116,975 psi, which is about a 7% drop in capability.
I also tested this oil to find out its onset of thermal breakdown, which was 255*F. The onset of thermal breakdown of conventional motor oils is typically LOWER/WORSE than synthetic motor oils.
For traditional American flat tappet pushrod V-8 engines, I recommend the following:
Stock or lightly modified versions of those engines are best protected by motor oils that provide at least 100,000 psi or higher film strength/load carrying capability/shear resistance.
Racing or High Performance street versions of those engines are best protected by motor oils that provide at least 120,000 psi or higher film strength/load carrying capability/shear resistance.
So, this 10W40 Quaker State All Mileage, conventional motor oil performs so well, that it is even suitable for any traditional stock or lightly modified flat tappet engine. And it is even suitable for any traditional Racing or High Performance street flat tappet engine, as long as you can keep its oil temperature below 240*F.
However, this thicker 10W40 motor oil is ONLY recommended if you MUST use a thicker motor oil to maintain acceptable hot normal operating temperature oil pressure, or if you NEED a thicker conventional motor oil to help reduce excessive oil consumption. But, for most water-cooled, gasoline powered engines, 5W30 is “THE IDEAL” overall viscosity.
NOTE: Motor oil bottles will say, Synthetic, Synthetic Blend, or they will NOT specify what the oil is at all. If it does NOT specify, it is CONVENTIONAL motor oil. This oil’s bottle did NOT specify, but on-line it was listed as conventional."
I may give this one a shot on my next oil change in my 2005 4.0 Jeep Wrangler since it does have a minor rear main seal drip using synthetic oil.
"19. 10W40 Quaker State All Mileage, API SP, conventional = 126,055 psi
This is BY FAR THE BEST performing “CONVENTIONAL” motor oil I have ever tested.
This IMPRESSIVE (for a conventional motor oil) psi value is NOT an outlier value. I test every oil several times, then average all those values to arrive at the most accurate and representative value, that I post. This oil tested rather consistently, and none of its test values was very far off from this posted average. This is simply an excellent performing conventional motor oil.
This motor oil contains “seal swell/seal conditioners”. It was tested in Spring 2023.
zinc = TBD
phos = TBD
moly = TBD
The psi value of this new oil, came from testing it at the normal operating test temperature of 230*F. I went on to also test this oil at the much higher temperature of 275*F. At that elevated temperature, most hotter and thinner oils typically experience a drop in Wear Protection Capability. At that elevated temperature, this oil produced 116,975 psi, which is about a 7% drop in capability.
I also tested this oil to find out its onset of thermal breakdown, which was 255*F. The onset of thermal breakdown of conventional motor oils is typically LOWER/WORSE than synthetic motor oils.
For traditional American flat tappet pushrod V-8 engines, I recommend the following:
Stock or lightly modified versions of those engines are best protected by motor oils that provide at least 100,000 psi or higher film strength/load carrying capability/shear resistance.
Racing or High Performance street versions of those engines are best protected by motor oils that provide at least 120,000 psi or higher film strength/load carrying capability/shear resistance.
So, this 10W40 Quaker State All Mileage, conventional motor oil performs so well, that it is even suitable for any traditional stock or lightly modified flat tappet engine. And it is even suitable for any traditional Racing or High Performance street flat tappet engine, as long as you can keep its oil temperature below 240*F.
However, this thicker 10W40 motor oil is ONLY recommended if you MUST use a thicker motor oil to maintain acceptable hot normal operating temperature oil pressure, or if you NEED a thicker conventional motor oil to help reduce excessive oil consumption. But, for most water-cooled, gasoline powered engines, 5W30 is “THE IDEAL” overall viscosity.
NOTE: Motor oil bottles will say, Synthetic, Synthetic Blend, or they will NOT specify what the oil is at all. If it does NOT specify, it is CONVENTIONAL motor oil. This oil’s bottle did NOT specify, but on-line it was listed as conventional."
I may give this one a shot on my next oil change in my 2005 4.0 Jeep Wrangler since it does have a minor rear main seal drip using synthetic oil.