So you are saying if a more efficient filter protects a pre 1990 6-71 or 6v92 in a city bus diesel engine better that somehow correlates to better protection and longer engine life for a modern gasoline engine?
I know where the particles are coming from in the diesel but where exactly are they coming from in a modern gasoline engine?
Why are there so many stellar UOA's from engines that just use an OE filter eg Toyota's inefficient filters and go hundreds of thousands of miles and often to the junk yard with perfectly good engines in them? Fair question.
I have read the bus study and its almost totally irrelevant to today's gasoline engines yet you keep insisting on using it a some sort of Biblical reference. There is a reason a 6-71 needs a filter this size and it isn't so much wear metals as it is large amounts of coagulated carbon from burning diesel oil.
And a reason a modern 3.5 ltr gasoline engine can use one this size for 15k+ with no issues. I realize size has nothing to do with efficiency but it does have to do with loading capacity so the manufacturer feels a filter this size is more than adequate to warranty the engine with and it is.
There is no proof one way or the other using this filter over that one will result in longer engine life or less wear in a modern gasoline engine.
There is certainly nothing wrong with the Ultra but there is no valid reason to use it over another filter, an OE Toyota filer for example will protect the engine just as well over the OCI listed or is Toyota selling oil filters they know will shorten the engines lifespan deliberately?
This is why the bus study is irrelevant and why the fact they were diesels does make a difference.
Quote:
The implications of diesel soot particles on wear of the engine have been investigated by various researchers. Gautam et al. [15] found that the wear of lubricated engine components is proportional to the soot concentration in the lubricating oil. Studies by Sato et al. [16] and Green et al. [14] confirmed this observation and discovered further that the effect is more significant for thinner films, e.g. in the valve train. As such, the camshaft undergoes wear in the form of surface degradation and reduction in cam diameter, resulting in increases in friction and impeded cylinder gas exchange due to reduced valve amplitudes respectively. Consequently, the engine efficiency is reduced.
https://www.sciencedirect.com/science/article/pii/S0008622318306122