The 378 was Peterbilt's main truck from 1987 until the 2007 model-year keeping the nameplate's touch longnose styling. Obtainable in standard (119\" BBC) and extended hood (127\" BBC) lengths, the 378 is the last normal over-the-road truck available with the aluminum hood. Changing the "359" in 1987, it stayed in production till March 2007 using the final 1000 378s named the "Legacy Course 378." Peterbilt dropped the long-running "American Class" inside in 2005 with the ending of the "Ergonomic Dash". The chief dash colour was black until the 2000 model year, that was the last year for your "First Dash"; you can possibly purchase it in grey, tan, or black. Currently Peterbilt doesn't provide the "2006 Dash" in black.

Peterbilt also made modifications to the cab doors in late 2004 the mirrors went from the doorway to the cab and also when the port window post was removed. (Interestingly the "first taxi" from Fageol had no port windows and consequently a retro-look was attained). A much larger peep window was received by the passenger door. For 2006 and 2007 the doors received a fresh window with an angled-towards-thehood lower ledge allowing for added visibility, notably for the right. Back corner windows also became accessible.

28\" window. The Unibilt Daycab window size became common around 2003.

Autobot leader Optimus Prime's alternative manner in the 2007 Transformers movie is a 1997 Peterbilt Model-378 Extended Hood truck
Three changed 378s appeared in the 2007 liveaction movie "Transformers" as Autobot-leader Optimus Prime's vehicle/disguise mode. There is much argument over this within the Transformers enthusiast community because Optimus Prime is nearly always portrayed within the many cartoon series for a flatnose cabover semitrailer truck (or after for a fire-engine); his film incarnation will be the next with the extended nose conventional cab (following his character in 2002-03's Transformers: Armada).

2002 Peterbilt 378