NOVELTY - The pump has a pendulum (10) in a chamber in a frame on the vehicle wheel that oscillates due to rotation of the wheel and which is connected to and drives a reciprocating piston (26) located in a chamber so that the piston discharges gas from an outlet. The pendulum also generates electricity using piezoelectric stacks or biomorphs or using magnets and pickup coils.    USE - For mounting either inside a motor vehicle tire or on the outside of their rims.    ADVANTAGE - Ensures that the air pressure in tires is kept at an optimum level so that fuel consumption does not increased, vehicle handling does not worsen and the performance of braking and suspension systems are not adversely effected. Can be conveniently and simply installed and does not require mechanical modification of the axle or its supporting structure. Can deliver electrical power to onboard electrical systems.    DETAILED DESCRIPTION - The pump has a frame adapted to rotate as the vehicle wheel turns which includes a chamber with an outlet within which a piston is reciprocally mounted such that reciprocal movement of the piston discharges gas out of the outlet. A pendulum is pivotally mounted in the frame so that it is freely movable within the chamber and is connected to the piston so that movement of the pendulum causes reciprocal movement of the piston.    The length of the pendulum arm and the point (16) about which the pendulum pivots are selected so that the pendulum is capable or resonant oscillation within the chamber at substantially all rotational speeds of the frame. The movement of the pendulum also creates electrical energy, either through piezoelectric stacks or biomorphs being positioned at the extreme points of travel of the pendulum in the chamber or through the pendulum being formed from a magnetized or ferromagnetic material and the electrical energy being generated in pickup coils as the pendulum moves.    DESCRIPTION OF DRAWING(S) - An idealized representation of one embodiment of the tuned resonant oscillating mass pump mounted on a wheel.    Pendulum (10)    Pivot point (16)    Reciprocating pistons (26)