DURAMAX is a General Motors Diesel V8 engine family for trucks. The 6.6-liter Duramax is produced by DMAX, a joint venture between GM and Isuzu in Moraine, Ohio. ... This engine was initially installed in 2001 Chevrolet and GMC trucks, and has been an option since then in pickups, vans, and medium-duty trucks. There are two different colors to choose from (Red or Blue).