As you may have noticed, mechanical advantage and velocity ratio go hand in hand - you can‘t jack the car up one metre and only move the jack handle half a metre without applying a huge effort. In an ideal world, mechanical advantage and velocity ratio would always equal each other on a given system. In other words, if you lifted a car through 5cm by moving the jack handle through 500cm then the effort required would be one hundredth of the weight of the car. Unfortunately, in the real world, friction, air resistance and other losses mean that this ideal situation is never actually achieved. Systems are inefficient. The efficiency of a system can be calculated by dividing its Mechanical Advantage (MA) by its Velocity Ratio (VR) and then multiplying by 100 to get a percentage.
Efficiency = MA/VR x 100%