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The ninth annual Valvoline Detroit Grand Prix went to a Havoline driver: Michael Andretti, who took his first win of the season for Newman/Haas Racing. Coming off of a frustrating fifth place in Milwaukee despite leading the most laps, Andretti was similarly dominant in Detroit: after winning the pole, he led the most laps once again, but this time finished the job. 1987 champion Bobby Rahal and IndyCar rookie Eddie Cheever completed the podium.

The event was the second of three held at the downtown Renaissance Center, before moving to Belle Isle for 1992. Support race winners included Irish Formula 1 alum Tommy Byrne in the American Racing Series (Indy Lights) and Scott Sharp in SCCA Trans-Am.