He debuted a Ford Mustang Cobra R in Motorola Cup competition in 1996 with teammate Nick Longhi and competed part-time with that car in the 1997 and 1998 seasons.
The team captured their first class win in the 6 hour race at Watkins Glen International with teammates Longhi and Jeff Segal.
Emil Assentato with his teammate Jeff Segal captured the 2010 Rolex GT Class Championship in #69 Fxdd Mazda RX-8, winning three races as well as finishing in the top five at almost all the events.
In that historic 2012 season (as it marked the return of Ferrari to Grand Am competition after a ten-year hiatus) Emil captured a second Rolex GT Class Championship with teammate Jeff Segal.
In Emil's last season he teamed up with Anthony Lazzaro in which they placed fourth in the Championship and proved to be a car to contend with at all events they competed in.