Western Star · Class 8 on-highway tractor
Western Star 5700XEDetroit DD15 14.8L (standard), Cummins ISX/X15 15.0L
Built 2015-2026
Engine Detroit DD15 14.8L (standard), Cummins ISX/X15 15.0L
Sources checked 116 of 130 (89%)
What it is
Western Star's on-highway aerodynamic tractor, introduced in 2015. The 5700XE brought highway aerodynamics to the Western Star line, powered by the Detroit DD15 and the DT12 automated transmission.
Pick a folder
Fluids & Fill Amounts5 entriesBolt Tightness52 entriesWhen to Service10 entriesWarning Lights & Codes30 entriesHow to Fix It78 entries
The truck itself
Engine options
Detroit DD15 14.8L (standard), Cummins ISX/X15 15.0L
Horsepower
400-505 hp (DD15); 400-605 hp (X15)
Peak torque
1,550-1,850 lb-ft (DD15); 1,450-2,050 lb-ft (X15)
BBC
128 in
Transmission
Detroit DT12 12-speed AMT (standard)
Transmission
Detroit DT12 12-speed AMT; Eaton Fuller manual or automated
Front axle
Detroit / Hendrickson 12k-13.3k
Rear axle
Detroit / Meritor 40k-46k tandem
Weight class
Class 8 - up to 80,000 lb
Before you order anything
Options change the numbers
The 5700XE was introduced in 2015 as Western Star's first true highway aero tractor. It shares the Detroit DD platform with the 4900 and 57X. The DT12 is the standard transmission from 2015.