What is the main consequence of having insufficient brake fluid?

Insufficient brake fluid directly affects the braking system's ability to function effectively. Brake fluid is crucial for transmitting hydraulic pressure from the brake pedal to the brake components at the wheels. When the fluid level is low, the system cannot generate the necessary hydraulic pressure, leading to a decrease in braking performance. This translates into a longer stopping distance, reduced responsiveness, and may even result in complete brake failure if the fluid is critically low.

In contrast to decreased performance, improved braking distance, increased brake pedal sensitivity, and enhanced stopping power would imply more effective braking capabilities, which is not possible with insufficient brake fluid. Therefore, the correct understanding highlights that low brake fluid levels compromise the entire braking mechanism, significantly impacting safety.