A dry clutch uses dry friction to transfer power from the input shaft to the output shaft, for example a friction disk pressing on a car engine's flywheel. The majority of clutches are dry clutches, especially in vehicles with manual transmissions. Slippage of a friction clutch (where the clutch is partially engaged but the shafts are rotating at different speeds) is sometimes required, such as when a motor vehicle accelerates from a standstill; however the slippage should be minimised to avoid increased wear rates.