According to extensive tests in racing, BRAKE FLUID DOT 5.1 can be used in on-road and off-road motorcycles, as well as passenger cars and commercial vehicles where a brake fluid complying to the FMVSS 116 DOT 5.1. BRAKE FLUID DOT 4 is ideal for hydraulically operated disc and drum brakes of motorcycles, passenger cars, commercial vehicles and machines. It can be used wherever a brake fluid is required according to the FMVSS 116 DOT 4 specification.� specification is required.