DOT 5.1 is a type of brake fluid that is glycol-based and designed for high-performance vehicles. It has a higher boiling point than standard brake fluids, which helps prevent brake fade during intense driving conditions. This makes it suitable for both racing and everyday use in vehicles that require superior braking performance. Unlike DOT 5, which is silicone-based and not compatible with other brake fluids, DOT 5.1 can be mixed with DOT 3 and DOT 4 fluids. It is important to regularly check and replace brake fluid to maintain optimal braking efficiency and safety in vehicles.