Synthetic Oil

Jim

I have over ten vehichles, most of them being from the late fifties and early sixties. After initial break in on a rebuild, I ALWAYS switch to Mobil 1 with the single exception of my two corvairs. They tend to leak anyway, so I did not wish to compound the problem. Air cooled corvairs run a little hotter, and the seals were kind of a weak spot on them so I stay with regular Mobil.

I have had several years experience with Mobil 1 and recommend it wholeheartedly. The problems that have been mentioned here by others are a result of not changing the oil often enough in my opinion. They DO NOT sludge up if changed regularly. You cannot go 25,000 miles between changes like they used to claim, but if you change it about as often as regular oil, the engine remains clean enough inside to eat off of.(So to speak).

On engines in good condition, I have NEVER experienced a problem with leaks or seepage from synthetic oil. That has never occured in any of my projects. However, I have to admit that I do not use it in old engines with already existing deposits.

Bottom line--if your goal is to obtain extreme longevity then you should go with Mobil 1. If you will trade it off around 100k miles or so, it will NOT PAY.

Just my two cents

We run a fleet of 90 school buses and run it.

That being said, I had two personal Plymouth Voyagers, all with some miles on them. Thought the synthetic would be good. Well put it in, they leaked oil like a seive. The seals and gaskets all leaked. After two changes switched back and the leaks quit.

So, from my experience, if you want to use synthetics, I would use them from the get go. You might try them if your vehicle has miles and see if you develop leaks. If not, you win.

Only thing I can see, is that synthetic doesn't break down as easily as regular, but it does get contaminated, so I would still not go long long times between changes.

Just my "shadetree" opinion.

JU

My automotive experiences with them have been less then stellar though.

In the engines I've used it in, they sludged. Upon studying synthetic oils further I discovered this is natural as synthetic oils will not suspend contaminates the way standard oils will. Hence, sludge.

Leaks increased substantially. What was a damp gasket would become a leak with synthetics, a leak would become a stream. Again, this is natural with synthetic oils. They have a superior lubricity, and this is a trait of superior lubricity. It's also why the bottles of synthetic oil feel oily, and why the shelves under them tend to be oily.

My lowest mileage vehicle has over 200,000 running standard Castrol GTX. Other vehicles of mine are approaching half a million miles. No internal repairs on any of these vehicles, ever.

I will use a synthetic oil on a turbine. But in a truck car or tractor, in my experiences, it is overkill on the lubricity, and underkill on cleaning.