For the 1982 season, Team Penske introduced their new PC10 chassis. Advancement in the design of the PC9B, including a larger underwing, significantly improved the aero grip. With Bobby Unser's retirement at the end of 1981, Mears became Team Penske's lead driver and he led the driver development of the PC10 during pre-season testing. Throughout his career, Mears enjoyed working with the engineers to understand and improve chassis design.

Entering the Month of May 1982, Mears had already won the first two races of the season, and he qualified the PC10 on pole position with a four-lap average of 207.004 mph, a new track record, and over 2.5 seconds faster than second-place, his teammate Kevin Cogan. After a crash at the start of the race, resulted in a red flag for clean-up, the field settled into the race and Mears led 77 laps, as late as Lap 159, setting the stage for a late-race duel with Gordon Johncock. Despite a hard charge from Mears in this PC10, Johncock held him off and won by just .16 of a second, at the time the smallest margin of victory in “500” history.

For the remainder of the season, Team Penske and the PC10 were the combo to beat. Mears followed up his near-victory at Indianapolis with two wins and four top-five finishes, clinching the third and final CART series championship of his career.