Reply to "Oil Recommendations"

While synthetics are great for breakdown from high temperatures, I am not a big fan of "Pure" synthetics. Here's why.

In the 90's Mobil produced a full synthetic for airplanes. Within a short period of time aircraft after aircraft began to have trouble. Engines were not making it to their overhaul interval and propeller governors were failing.

The problem came from the lead in the fuel. Aviation fuel still has lead in it. It was soon found that the FULL synthetic oils could not break down the lead. This lead to very fast sludge build ups which was damaging engines and locking up the propeller governors.

Today we have very clean gas but there is still 2 concerns with full synthetics. First is it can not break down carbons as well as blends and natural oil. This is not to say synthetic is not good oil. It just does not have the ability to break the carbons down as well. They add additives to help this but with each added percent of additive the less percent of oil you have.

Second is the adhesion to bearings is not as great because of its slipperiness. I know some one who tried a full synthetic and first time on the track wiped out a couple bearings. Changed the bearings and the oil back to a blend and has not had another problem in years.

In a corner momentary oil starvation the bearings can glide on a momentary film. With synthetics it slides off faster. BUT again they have additives for this which means...less oil content.

Now we run full synthetics in our jets but they are not exposed to carbon blow by nor interruptions in oil supply of any kind as well as far better filters. 3000hrs latter and these oils are still as clean as baby oil.

My vote is for a good blend.