HOW IT WORKS: Use AR6400-D first for a deep clean (12 oz treats 30-40 gallons), then use AR6500 at every fill-up for ongoing protection (40 oz treats up to 400 gallons). IMPROVES LUBRICITY (ASTM D6079): AR6500 is tested to improve lubricity by 43% to protect fuel system components, including wear-sensitive parts like the CP4 pump.
