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Originally Posted by sensi09
Quote:
Originally Posted by PandaM3
I got that statement from one of the oil forums... but looking at the spec sheet... I agree... cold flow is pretty bad with TWS10w60
Anyone have any idea on what spec sheet values correspond with film strength? I think that is an important value to keep the bearing metal from touching too...
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I believe in general the higher the viscosity, the greater the film strength. You can look at the viscosity of the oil, the kinematic viscosities as well as the HTHS.
I look at a high HTHS as the ability to protect at high temps, but it's also "an indicator of an engine oil's resistance to flow in the narrow confines between fast moving parts in fully warmed up engines." http://www.kewengineering.co.uk/Auto..._explained.htm
Interesting balance between the tight bearing clearances and protection at high temps. |
Castrol 10w60 has an hths of 5.2, but a viscosity kinematic at 40 degrees (cold start) of 160
Motul 300V 5w40 has hths of 4.1 and 10w40 is 4.2 with viscosity kinematic of 81 and 90 respectively
Mobil 1 0w40 has hths of 3.8 and viscosity kinematic of 75
So the castrol would seem to be best at protecting bearings if you can drive it like a grandma when cold until the temp timer on the oil level pops up which takes 10 to 15 min for me on cold socal mornings
Otoh motul 300v could be a good compromise so long as you can get it close to the same price as the castrol for 9 liters and it has much better cold start flow as well as a higher flash point