Detroit DD13
The lighter sibling, and around 400 pounds lighter than the DD15, which is payload on a weight-sensitive lane. Perfectly capable for linehaul under 80,000 pounds and noticeably thriftier.
Output
370-505 hp
1250-1850 lb-ft peak torque
Fuel per mile
$0.513
at 7.9 mpg and $4.049 a gallon
Fuel a year
$61,504
over 120,000 miles
In-frame overhaul
$20k-$29k
rough, and shop rates move it
In the exhaust
DPF and SCR, one-box
The first greenhouse gas phase targets the whole vehicle rather than the engine, so this era is as much about aerodynamics, tyres and axle ratios as combustion. Downspeeding becomes standard: tall gears, low cruise revs.
Known issues
The same aftertreatment items as the DD15. The engine itself is not the complaint.
Verdict
If you are not running heavy and not running mountains, the 13 litre gives up very little and returns weight and fuel. More owner-operators should consider it than do.
Trucks it is offered in
Freightliner Cascadia
7.2-9 mpg
Freightliner · 2008 to 2017Freightliner Cascadia (first generation)
6.2-7.4 mpg
Freightliner · 2002 to presentFreightliner M2 106
6.5-8.5 mpg
Western Star · 2020 to presentWestern Star 49X
4.6-6.3 mpg
Western Star · 2015 to 2023Western Star 5700XE
7-8.6 mpg