Motor Fuel Sales Competition Improvement Act of 1987 - 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; or (2) prohibiting such a dealer from converting a fuel storage tank or dispenser for the sale of fuel supplied by another producer or refiner.

Prohibits 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 any large integrated refiner from operating any service station in the United States. Permits such refiner to own all or part of a service station, provided it does not engage in selling fuel at such service station through any employee, agent, or representative.

Provides for the enforcement of this Act. Provides that this Act shall not supersede any comparable State law to the extent that compliance with the State law can be accomplished consistent with this Act.