Nope. Caked-up intake valves and carbon built up from oil consumption. My 30 year old shitbox truck has nearly 400k on the original engine running premium the whole time. It's designed for that, wheather or not the manufacturer recommends it. Notice that they never discouraged it?
If only you had seen a engine with 1/2 million miles on it run on propane. Shiny as brand new.
Nope. Caked-up intake valves and carbon built up from oil consumption. My 30 year old shitbox truck has nearly 400k on the original engine running premium the whole time. It's designed for that, wheather or not the manufacturer recommends it. Notice that they never discouraged it?