Western Star has launched a new model in North America – the 49X, built “from the ground up” for vocational applications.
Terming it “the next generation of tough,” the 49X has a stronger, lighter chassis, a new X-series cab and debuts the Detroit DT12 Vocational automated manual transmission.
Australasian Western Star distributor Penske Australia New Zealand, says a 49X local test programme will begin next year, with the new model released here in late 2022 or early 2023.
The 49X can be mated to the Detroit DD15 Gen 5 engine, rated at up to 505 horsepower/376 kilowatts and 1750 lb ft/2372Nm of peak torque, or the DD16 – offering up to 600hp/447kW and 2050 lb ft/2779Nm.
The DD15 Gen 5 comes with a 60 lb (27kg) powertrain weight reduction, contributing to the 49X’s lightweight status – over 350 lbs/158kgs lighter than a comparable current Western Star 4900.
The cleansheet design of the new Western Star makes that possible primarily through its new, purposebuilt frame and the lightweight X series cab.
Western Star says that the 49X brings together for the first time in a vocational truck “the cutting-edge technology, power and performance offered by the industry-leading Detroit Assurance suite of safety systems, the all-new Detroit DT12 Vocational Series of automated manual transmissions, and the enhanced Detroit DD15 Gen 5.” The latter delivers remote diagnostic services to increase uptime and productivity.
“With the 49X, Western Star delivers on our promise of tough, while introducing segment-first safety features, an operator-focused experience and easier upfit solutions that will keep our customers’ businesses running smoothly,” says David Carson, senior VP, vocational segment, Daimler Trucks North America.
Development work on the cab was the most extensive in Western Star history and included multiple cab crush tests to ensure cab integrity in a rollover. Full-vehicle shaker tests replicated 1.35 million kilometres of use to test the innovative cab mounts system. It is the segment’s largest cab, with 10-13% greater space than competitors.
In all models, a wraparound dash puts the driver command centre and B-panel in easy line of sight of the operator. 
The DT12 Vocational AMT series, rated up to 330,000 lbs/149,685kgs, was validated in around 34million kms of testing, to prove its performance and durability. It includes side PTO capabilities and comes with unique work application modes and shift map strategies including rock-free, offroad, power launch and paver modes – the latter allowing the truck to shift from Neutral to Drive without touching the brake pedal when pulling away.
Western Star says that the 49X has “the most advanced collision mitigation system in the vocational market.”
It has sideguard assist, active braking assistance, tailgate warning, adaptive cruise control (down to a stop), lane departure warning, video capture, intelligent high-beam and automatic windscreen wipers and headlights.
The safety features extend to ergonomic cab access, with a 70-degree door opening angle, five hand holds, and wider, staircase-style steps.
The 49X’s best-in-class visibility comes from a sloped bonnet made possible by splayed frame rails, a lowered engine position and under-bonnet air filtration, a 28% larger single-piece windscreen and an optional rear window that’s 77% larger than on the 4900. 
The DD15 Gen 5 has a new aftertreatment system that has a single DPF, needs less space and extends service intervals. It also achieves high torque at lower revs.
Penske Australia NZ president Randall Seymore says the company has worked very closely with Daimler Trucks for several years on the development of the 49X and will continue to do so in the leadup to its local launch.
The local test programme is aimed at “ensuring the new trucks are a perfect fit for our local conditions and applications.”