A vehicle (10) with a rotary sliding vane engine (14) including a compressor (18), a combustion chamber (20), and a motor (22) in which the braking is done by connecting the rotor of the compressor (18) to a wheel (12) and braking rotation of the rotor by controlling the gas flow through the rotary sliding vane compressor (18), such as by varying the outlet to increase the pressure ratio. This eliminates the conventional friction brakes. The compressed air generated during braking is fed to a surge tank (28) for later use in operating the vehicle engine (14), thus recovering a portion of the kinetic energy of the vehicle (10). The rotary slide vane motor (22) can also be used as the brake by controlling the inlet thereto. The compressor (18) and motor (22) can be separate units or portions of one unitary rotary sliding vane device. The compressor brake and motor-brake can be used together or separately and as integral or separate parts of a rotary sliding vane engine (14) and also with other different types of engines.