There is no definitive answer to this question as it largely depends on personal preferences and needs. However, many experts consider the 2006 model to be the best Duramax engine ever made. This is because it was the first year that GM introduced major changes to the Duramax platform, including a new 6.6L turbo-diesel V8 engine that significantly increased power and torque. The 2006 Duramax also featured updated styling inside and out, as well as a host of new technology features that made it more comfortable and convenient to own.