Western Star · Class 8 vocational/heavy-haul tractor
Western Star 4900Detroit DD13/DD15/DD16, Cummins ISX/X15, Detroit Series 60 (legacy)
Built 2000-2026
Engine Detroit DD13/DD15/DD16, Cummins ISX/X15, Detroit Series 60 (legacy)
Sources checked 121 of 135 (90%)
What it is
Western Star's flagship vocational truck. Set-forward, set-back, and extreme-duty configurations. The 4900 handles everything from logging to heavy-haul to dump work, with up to a 1,875 sq in radiator and 600 hp.
Pick a folder
Fluids & Fill Amounts7 entriesBolt Tightness53 entriesWhen to Service12 entriesWarning Lights & Codes30 entriesHow to Fix It77 entries
The truck itself
Engine options
Detroit DD13 12.8L, DD15 14.8L, DD16 15.6L, Cummins ISX/X15 15.0L, Detroit Series 60 14L (legacy)
Horsepower
350-600 hp
Peak torque
1,250-2,050 lb-ft
BBC
123 in (XD extreme duty)
Radiator
1,500-1,875 sq in depending on engine
Transmission
Eaton Fuller 10/13/15/18-speed manual or UltraShift; Allison 4000/4500/4700 automatic; DT12 from ~2015
Front axle
Meritor / Detroit 12k-22k (set-forward or set-back)
Rear axle
Meritor / Detroit 40k-77k (tandem or tridem)
Weight class
Class 8 - up to 92,000 lb; GCWR up to 250,000 lb for heavy-haul
Before you order anything
Options change the numbers
The 4900 is Western Star's longest-running model, still in production. Early models (2000-2010) commonly carried the Detroit Series 60 or Cummins ISX. Modern 4900s carry the DD13/DD15/DD16 or Cummins X15. The XD version is for extreme duty with all-wheel drive available.