SEAFOAM is great! I put it in my 86 325es with 170,000 miles on it. Its great for high mileage cars, and safe. In my owners manual it says, do not add additives to the engine, but seafoam is not a chemical. You can put it in ANY engine, gas or diesel, 2 or 4 cycle engine, put it in the oil (crankcase), in the gas tank, and the vacuum hoses! I didnt think about it until I read this, thanks for the tip 325isBMW1988!!