Efron co-stars with Robert De Niro in the comedy about a conservative young man (Efron) who goes on a party-hearty road trip with his wild-man grandfather (De Niro).
The film is due for release in the U.S. Jan. 22, 2016.
Efron played a high school basketball player who gets drafted into the school musical in the original "High School Musical" TV movie, released in 2006.
Watch the trailer below: