Originally Posted By: A_Harman
Infineum sounds pretty lukewarm to fuel economy improvement by using ever-thinner oils. But they recognize that OEM's have to play the game because of CAFE penalties.
Quote:
Infineum studies indicate that, in some engines, reducing lubricant viscosities to 2.3 HTHS presents little risk of engine component wear. Below this level, specific engine components, for example the top ring and bearings, observe higher wear rates. To ensure ultra low viscosity lubricants deliver fuel economy and wear protection it is becoming increasingly important to co-engineer the vehicle hardware and lubricant system.
So the trend toward lower HTHS is beginning to require engines be redesigned to run the thinner lubricant. Isn't this a case of the tail wagging the dog?
Careful, 'less you get labelled a continual purveyor of misinformation.
Honda have mentioned in a couple of papers that they are increasing bearing projected area and reducing clearances to adopt lower viscosities...both of which increase the drag on the bearings.
Which makes me think that they are chasing an overall friction reduction mid stroke of the piston (while transport engine manufacturers are looking at TBCs to reduce the mid stroke viscosity.
There is no rational reason to make and lubricate an engine to last the equivalent of three bodies, do they are going to make durability sacrifices (Honda calls it acceptable durability) if it gets them some more CAFE credits.
If the bottom end is getting redesigned for durability in a lower viscosity world, the economy ramifications if an owner backslides to the 30s in their stash would be interesting to behold.
