Tuck,
Where did you find that cool article? I have huge respect for Gordon Jennings. Interresting article, but written in 1978 before the mainstream of synthetics. They may be right - and a great topic for dicussion! I base what I do on past experiences. I am the mechanic I am because of all the engines I have seized and exploded (that doesn't sound very good). I raced my 1978 Husky 390 for its race season using 32:1 penzoil (mineral). Numerous piston seizures and couple of blown rods was quite common over a long race season. In 1979 I got a new 400 maico and this cool Belray MC-1 sythetic oil that recommended 85:1 on the bottle. That season I got 52 pro races out of that engine, no seizures no blown rods, nada. On rebuild it was worn, but carbon free, intact and running. I was hooked and have been a devout Belray fan ever since. I would love to see that test applied to a modern engine and comparing castor to mineral to synthetic at say 20:1 40:1 60:1 and 100:1 to see what results they get. Cam.