579, 389 and vocational model boundaries
Peterbilt's aerodynamic 579, traditional 389 and vocational 567 serve different buying conversations. A sleeper-equipped tractor, set-forward or set-back axle, body-builder chassis and heavy-spec tractor should not be compared as interchangeable merely because they share a red oval.
Build variation is central
PACCAR and Cummins engine families and several transmission choices may appear by year and application. Confirm cab or sleeper, wheelbase, axle ratings, rear ratio, tanks and ordered safety equipment from the individual build.
Peterbilt inspection priorities
For highway examples, inspect aerodynamic panels, sleeper systems and evidence of fleet duty. For traditional or vocational examples, give extra attention to hood and cab mounts, steering, frame, suspension, PTO or body integration and undocumented modifications.
