What type of gas treatment can be used?
most fuels have cleaners built in,, avoid alcohol blended fuel [shell] if possible
You could use any of them, really. I've never used it, but I've heard great things about Techron. I need to pick some up.
ZMAX is the best. works in my $50,000.00 street engines.......
Looking for a Used 3 Series in your area?
CarGurus has 38,438 nationwide 3 Series listings starting at $1,700.
Search BMW 3 Series Questions
BMW 3 Series Experts