Originally Posted By: HammerHead0313
I tested the theory and proved the tolerance between internal engine components and your engine oil selection is true. Tighter the tolerance, thinner the oil. Test vehicle was a 2013 Dodge Ram RCSB 5.7, manufacturer recommended 5w20 switched to 5w30 weight oil. While canyon racing in north Georgia mountains my oil sump temperatures were 12-16 degrees hotter than the 5w20 running the thicker 5w30. Why? Because internal engine components are cooled by oil directly and cooled by coolant indirectly. Thinner oils flow better than thick oil's pulling more heat from Internal engine components and lubricate more effectively. Thicker oil's flow slower through internal engine components pulling less heat from the engine, Drive up bearing temperatures and the oil meets or exceeds it thermal break down point. Oil in these areas of the engine can be 90 degrees hotter than the oil sump temperatures. As we all know oil is application specific, and the clearances between internal engine components is something that should be considered when making your oil selection.
You’re missing the point. Engines can operate on 0w-20 all the way to 20w-50 and the grades between. For the daily driver 0w-20 provides adequate protection and allows OEM to claim better mpg. Take that same engine and canyon race it with 0w-20 and you may have some bearing issues once the oil gets hot.
Yes 5w-30 will run hotter. It is actually heated by friction as it is pumped through the bearings. This is where the mpg gains of thinner oil come from. They have less frictional pumping losses through the bearings and other parts. it also picks up heat from the pistons and whatnot. The key here is that even though the 5w-30 was hotter, it was still thicker in the bearings and other parts of the engine than the 0w-20. That gives a thicker oil wedge for the bearings to float on as you’re flogging the engine down the canyon.
Another example. The Ford Mustang with the Coyote 5.0 V8 calls for 0w-20 for everyday use. However if you get the track pack, 5w-50 is recommended. Same engine, 2 different recommended oil grades based on operating conditions.
I tested the theory and proved the tolerance between internal engine components and your engine oil selection is true. Tighter the tolerance, thinner the oil. Test vehicle was a 2013 Dodge Ram RCSB 5.7, manufacturer recommended 5w20 switched to 5w30 weight oil. While canyon racing in north Georgia mountains my oil sump temperatures were 12-16 degrees hotter than the 5w20 running the thicker 5w30. Why? Because internal engine components are cooled by oil directly and cooled by coolant indirectly. Thinner oils flow better than thick oil's pulling more heat from Internal engine components and lubricate more effectively. Thicker oil's flow slower through internal engine components pulling less heat from the engine, Drive up bearing temperatures and the oil meets or exceeds it thermal break down point. Oil in these areas of the engine can be 90 degrees hotter than the oil sump temperatures. As we all know oil is application specific, and the clearances between internal engine components is something that should be considered when making your oil selection.
You’re missing the point. Engines can operate on 0w-20 all the way to 20w-50 and the grades between. For the daily driver 0w-20 provides adequate protection and allows OEM to claim better mpg. Take that same engine and canyon race it with 0w-20 and you may have some bearing issues once the oil gets hot.
Yes 5w-30 will run hotter. It is actually heated by friction as it is pumped through the bearings. This is where the mpg gains of thinner oil come from. They have less frictional pumping losses through the bearings and other parts. it also picks up heat from the pistons and whatnot. The key here is that even though the 5w-30 was hotter, it was still thicker in the bearings and other parts of the engine than the 0w-20. That gives a thicker oil wedge for the bearings to float on as you’re flogging the engine down the canyon.
Another example. The Ford Mustang with the Coyote 5.0 V8 calls for 0w-20 for everyday use. However if you get the track pack, 5w-50 is recommended. Same engine, 2 different recommended oil grades based on operating conditions.
