My Oil, Lubricants, Engines & Misc experience.

In 86 I bought a Mazda b200 pickup truck brand new off the lot. It was my first brand new vehicle ever. I drove used cars up till then. At that time I was convinced that Amsoil (same as Moble1) was the best thing ever for an engine. Never used it before. So - I left the mineral oil in the engine for the recommended 2000 miles - and put it in. At 60,000 I took off the valve cover to adjust valve lash, and the first thing I noticed was how freaking clean everything was. Zero deposits.. the inside of the valve cover was as clean as the the day it was made. Also... no adjustment was necessary. I had read that engines with 100,000 miles were just broken in. So, I also drained out the manual 5 speed overdirve transmission and put in something like 0-90w
gear oil in the thing. WOW! It shifted so slick! I could REALLY tell that that transmission was slicker that you know what! In the cold it was amazing! So I figured - put it in the rear end too. I can't present any data to prove that the thing was more fuel efficient, but it certainly seemed to be. I was bragging to everyone I met.. about this synthetic mythical fluid - but more times than not, I'd get someone that would tell me: "You just wait.. you will have leaks." I said: "that is a myth - not true." Well to make a long story short, after 150,000 Miles I ended up with leaks in the engine main seals, the transmission seals, and the rear end seals. At $6.00 - 9.00 dollars per quart - I switched back to cheap mineral oil. However that truck did go over 300,000 miles.
Oh.. I should mention I also used Slick 50 in it.
Any comments about what you think is appreciated.

In the older style engines that are carbed, when you take out the standard oil and put in Mobil 1 or any other like oil, the RPMs at idle will go up about 100 RPM. With the new engines, they all are electronic controlled RPM so you don't notice the change. I use Mobil 1 in all my cars and have had pretty much the same results, the mileage goes up a few percent too because the engine isn't creating so much internal friction either.

Started using Amsoil in the 70's in a brand new dodge pickup, at the first oil change I used it for the first time. About two weeks later, my new wife came back to Valdez from Anchorage, about a 300 mile trip one way. She came into the house and said "What does a red light on the dash mean?", I said how long had it been on and she responded about 150 miles or so....

I was pretty freaked out and ran out to check the oil, the dipstick was full up to the top of the tube... The Choke on the old style carb was stuck in the closed position, it had sucked pure gas into the engine and down past the piston rings. I figured the new engine was shot. Pulled the pan off and checked a couple of rod bearings and found nothing, they looked new, well with about 2500 miles on them they should have been wiped from lack of oil lubrication on them. With that much gas, the oil qualities should have been shot, but since it was synthetic, it did still kept the engine lubricated in spite of about four gallons of gas in the crankcase. Used synthetic oil ever since and never wore out an engine, sold them running well too, with way over 100,000 miles on them to boot!

every thing i have runs 5w40 synthetic in it works on diesels and gas motors and i can even start my old school 6.2 at som amazingly cold temps with out plugging in