Porsche return to CART in its 1987 season fielding Al Unser in the #6 Quaker State Porsche, with the chassis and engine both being Porsche only competing at the Champion Spark Plug 300K at Laguna Seca Raceway. Unser would qualify 21st out of 24 cars and would retire in 24th place after only seven laps due to a water pump failure. For 1988 Teo Fabi would drive the #8 Quaker State March 88C-Porsche getting a best finish of 4th at the Bosch Spark Plugs Grand Prix at Pennsylvania International Raceway, Fabi would finish tenth in points. For 1989 Fabi would drive the #8 Quaker State March 89P-Porsche qualifying on the pole position at both the Budweiser / G.I. Joe's 200 at Portland International Raceway and the Red Roof Inns 200 at Mid-Ohio Sports Car Course getting the win at the latter. Fabi would also give Porsche their best finish on an IndyCar oval by finishing 2nd at the Marlboro 500 at Michigan International Speedway.