Motor Fuel Consumer Protection Act of 1991 - Prohibits any oil producer or refiner from: (1) requiring any retail motor fuel dealer to purchase more than 70 percent of its monthly retail sales of motor fuel from such producer or refiner; (2) restraining the dealer from purchasing any or all of his or her motor fuel requirements from a wholesaler of the motor fuel produced by such producer or refiner; or (3) contracting, combining, or conspiring with any other producer or refiner to violate the provisions of this Act.

Prohibits with a specified exception any dealer at a service station displaying a name or other identifying symbol of a refiner or producer from selling fuel not provided by such refiner or producer without providing notice at the point of sale.

Prohibits producers or refiners from operating any service station in the United States. Permits them from owning all or part of a service station, provided they do not engage in selling fuel at such service station through any employer, agent, or representative.

Provides for the enforcement of this Act. Provides that this Act shall not supersede any comparable State law.