Tim Cole wrote:
Oil filters were an option on legacy GM engines into the sixties.

The best studies I have found on full flow filtration comes from the railroads where they found that diesel engine wear was greatly increased with lack of filtration. However, the difference was so vast compared to gasoline engines I'd have to see a similar comparison for road going diesel.

One anomaly with Packards is that, with the proving grounds, they moved to full flow filtration but dropped it after the "senior" lines. That sort of supports the old timers wanting the most oil pressure they could get into those motors. Start pushing a Su8 to the limit and number two rod will launch into orbit.

One thing about those bypass filters being used on expensive heavy equipment is they filter down to very small micron levels. An important consideration given the sumps carry gallons and gallons of oil. What I don't understand is why engine builders haven't discovered rectification. Even Bugatti recommended heating oil on the stove to remove dissolved water.