Great, no hurt motor is awesome...
Amsoil has best oil, filters and systems.
Bought an 86 mazda pick up new. 325k and 13 years later i had changed oil about 4 times. Just replace filter and bypass filter and top off. Truck ran better and got better mpg than new. Just got tired of driving it so i sold it.
Learned about it from my friend in the 70's. He used it in his motocross dirt bike.
100:1 mix cut his rebuilds in half and bike ran better.
My 66 mustang has it and when i put my SSP 400 together it will have it.
The company has many more products and i dont keep up with it. I just put in the extended drain life oil with the narrowest viscosity rate, like maybe just 20w and then replace the filters according to mileage and top off. Oil doesn't break down and filters are very good. CAN'T GO WRONG WITH IT. And since i dont drain and replace oil much it isn't too expensive.
325K, 4 oil changes, 86 Mazda pick up ran like a top got 29mpg in stop and go driving.
When i removed valve covers to adjust it was clean as a whistle!. Plugs always CLEAN.
Same with my 66 mustang. Mustang gets 22mpg on hiway at 65-70 mph. All original. Grandparents bought it new. 289 2 barrel auto. I have put about 70k on mustang in 10 years. Replaced oil and filter 3 times. No bypass filter on it though. I would but just dont drive it enough and dont have any spare time to install.
Just my experience with it. Everyone is afraid of it.