ATF is multi vis (usually 5W10 or 10W20) with a bunch of detergent in the mix. It does a much better job of cleaning junk then either motor oil or kerosene. Cut 50/50 with either mineral spirits or kerosene, it makes a dandy penetrating oil. My Dad would cut it with either lighter fluid or gasoline for the same purpose, but, I didn’t tell you that. It is a good general purpose lube, as well, and for decades I have used it out of the bottle as bar oil in my chain saws, since it is about 20% the cost of brand name bar oil, and does as good a job, or better.
A buddy had a 409 engine with pistons solidly rusted in the bores for decades, and we filled up the holes with a mix of ATF and kerosene, and focused a heat lamp on the block for most of a month, keeping an eye on things once or twice a day. The pistons loosened right up. It probably wasn’t the brightest idea we had that day, but, we didn’t burn the shop down and that block then went into the shot blast cabinet and right after sold for a cool $1K.
I didn’t think it would work. I was wrong.
Best,
Ted
