Sounds like AFE has a higher level of friction modifiers (FM) than most oils. Be it in the organic or inorganic form.
I don't know if this is related, but the AFE has a high kinematic viscosity given it's HTHS viscosity, compared to regular M1 products. So it looks like different polymer VII treatment is used, either by type of VII or dose rate of VII. This could be associated with more thinner base stock being used in the AFE giving less frictional losses in the fluid, especially as the oil shears down a bit.
Regular M1 5W30, KV100 = 11.0 cSt, HTHS = 3.1 cP
Regular M1 10W30, KV100 = 10.1 cSt, HTHS = 3.0 cP
M1 0W30 AFE, KV100 = 10.9 cSt, HTHS = 3.0 cP
Shannow has linked to a few papers showing that a significant source of heat in the IC engine is due to frictional heating of oil in the bearings, not just chemical combustion in the cylinder.
To me a frictional saving should both increase fuel economy and reduce oil heat, so it sort of makes sense to me that a fuel economy oil is also a cool running oil.
I'm surprised that the 0W30 AFE is cooler than PP 0W20. A UOA of both would be nice, to look at their final viscosity.
I don't know if this is related, but the AFE has a high kinematic viscosity given it's HTHS viscosity, compared to regular M1 products. So it looks like different polymer VII treatment is used, either by type of VII or dose rate of VII. This could be associated with more thinner base stock being used in the AFE giving less frictional losses in the fluid, especially as the oil shears down a bit.
Regular M1 5W30, KV100 = 11.0 cSt, HTHS = 3.1 cP
Regular M1 10W30, KV100 = 10.1 cSt, HTHS = 3.0 cP
M1 0W30 AFE, KV100 = 10.9 cSt, HTHS = 3.0 cP
Shannow has linked to a few papers showing that a significant source of heat in the IC engine is due to frictional heating of oil in the bearings, not just chemical combustion in the cylinder.
To me a frictional saving should both increase fuel economy and reduce oil heat, so it sort of makes sense to me that a fuel economy oil is also a cool running oil.
I'm surprised that the 0W30 AFE is cooler than PP 0W20. A UOA of both would be nice, to look at their final viscosity.