Ultimate Test Drives… Detroit Diesel DT12 Test Drive Pt 2: Mastering Performance & Manual Modes

In part two of this in-depth exploration of a Detroit DT12 equipped Freightliner Cascadia, Jim spends most of his time comparing the performance of the DT12 transmissions three operating modes — economy, performance and manual. One thing Jim discovered was that, while most of the time the transmission does just fine on its own, there are still a few situations where a good driver can make the better shifting decision.