Western Star · Class 8 on-highway tractor
Western Star 57XDetroit DD15 Gen 5 14.8 L (DD13 Gen 5, DD16 optional)
Built 2023-2026
Engine Detroit DD15 Gen 5 14.8 L (DD13 Gen 5, DD16 optional)
Sources checked 116 of 133 (87%)
What it is
Western Star's long-haul truck, introduced for 2023. It uses the same Detroit engines and DT12 transmission as the Freightliner Cascadia, so engine service data matches.
Pick a folder
Fluids & Fill Amounts7 entriesBolt Tightness52 entriesWhen to Service11 entriesWarning Lights & Codes30 entriesHow to Fix It79 entries
The truck itself
BBC
128.5 in
Wheelbase
Up to 361 in
Configuration
Inline 6, 906 cu in / 14.8 L (DD15)
Horsepower
425-505 hp (DD15); 500-600 hp (DD16)
Peak torque
1,550-1,850 lb-ft (DD15)
Sleeper heights
60 in to 72 in
Transmission
Detroit DT12 12-speed automated
Front axle
Detroit or Hendrickson 12k-13.3k
Rear axle
Detroit or Meritor 40k-46k tandem
Weight class
Class 8 - up to 46,000 lb tandem rear
Before you order anything
Options change the numbers
Production began in the first quarter of 2023. Because it shares the Detroit DD platform, the DD15 fluid and torque figures carry over exactly.