In 1991, TriStar ran full-time with Hamilton and Country Time again sponsoring their Oldsmobile. Hamilton had four top-ten finishes and finished 22nd in points, winning Rookie of the Year honors. They began 1992 with no top-ten finishes, and later switched to Ford Thunderbirds, allowing Hamilton to get two top-ten finishes and finish 25th in points. After failing to finish higher than 15th eight races into the 1993 season, Hamilton was released. Greg Sacks drove for the rest of the season, with Dorsey Schroeder filling in at the road course races, and Loy Allen driving at Phoenix International Raceway.