In this episode, we talk about what preventative maintenance is and what two criteria determine if a preventive maintenance task should be assigned. The biggest pitfall that organizations often fall into when defining intervals for preventative maintenance tasks is revealed.
Bravo. MTBF is not useful for planning preventive maintenance. Increasing failure rate of oil helps. But what about using engine lifetime reliability or failure rate functions?
Chrysler asked for comparison of engine lifetime reliability functions of Camry, Accord, Passat, and Mitsubishi four-cylinder engines. Chrysler was considering changing the oil-change interval recommendation.
I estimated engine lifetime reliability function from aftermarket piston-ring-set sales (overhaul) and vehicle installed base by year, make, model, and engine. Toyota Camry and Honda Accord tied. Mitsubishi was worse, VW Passat was great: perhaps because of iron block and moderately high oil consumption.
I checked Subaru. Subarus used to leak oil because they didn’t use gaskets.
Following is Consumer Reports style report (circa 1992) on engine lifetime based on
SUBARU TRUCK, BRAT, 4-1781 (part number), 1.8L, (years) 82-87: great, great, fair, good, fair, good (I can’t figure out how to make emojis.)