Post
by Zedebee » Sun Mar 03, 2024 11:42 am
Chemically speaking, engine oil is virtually inert, and that applies to mineral oil as well as modern synthetics. The “additives” in modern oil may be more susceptible to degradation, but they are suspended in an inert media, so probably not. The engine is more a less a sealed system, so there is no reason why oil should degrade in the engine (over time) faster than in an opened plastic container.
Wear in the engine is only really a factor of the other crud which is circulating in the engine, which accumulates with use, not time, i.e. metal particles and soot. Metal particles are from friction inside the engine, for instance bearing wear; and soot from combustion products passing through seals and the gradual breakdown of oil under heat/pressure.
Changing the oil every year on a clean engine that only does 300 miles per year is bonkers in my opinion, but it looks great on the service history.
2003 Maldives Blue 3.0i auto
Previously: Maldives Blue 2.5i manual (its back!) and another, and a Monaco Blue 3.0Si coupe