The Western Star 47X is 10 inches shorter and 200 pounds lighter — spec-for-spec — than the 49X....

The Western Star 47X is 10 inches shorter and 200 pounds lighter — spec-for-spec — than the 49X. It’s suited for applications that are impacted by bridge laws, but still includes many of the new features first introduced with the 49X one year earlier.

Photo: Western Star

Western Star’s newest vocational chassis, the 47X – introduced last week by Daimler Trucks North America – is more than a scaled down version of the 49X.

While the 49X, introduced a year ago, is better suited to heavier applications like logging, oil field and heavy construction, the 47X is better suited for weight- and length-sensitive applications like concrete mixers, bulk haulers and dump truck setups bound by various bridge laws.

Vocational trucks are among the most complex vehicles anywhere. It’s a real challenge stuffing all sorts of different equipment from cranes to dump boxes to sander/plow setups onto very limited frame space. With the 47X, Western Star pulled through many of the new features introduced on the 49X, while offering vocational operators, including counties and municipal fleets, a chassis that accommodates much of the equipment they use in a lighter-weight, bridge-law-compliant package.

The most obvious difference is the shorter hood – 111.6-inch BBC for the 47X compared with 122-inch BBC for the 49X. With the optional “bridge-law bumper,” the bumper-to-back-of-cab measurement can be further trimmed to 110.8 inches. Wheel-base configurations up to 415 inches are available with the set-forward steer axle, while the set-back axle limits wheel-base to 361 inches.

“There are some 3,142-odd counties in the United States, and each one can have their own bridge-formula,” noted DTNA's Samantha Parlier, vice president of vocational market development, during a pre-release walkaround of the 47X with reporters. “Ten inches matters. Ten inches can be an extra 1,000 pounds [of payload], and it can be it can make the difference between a truck that's illegal to operate, and one that isn't.”

As well as being 10 inches shorter, the 47X is 200 pounds lighter –  spec-for-spec – than the 49X. Several frame rail options are available, including a 9.5-mil rail with the same RBM (resisting bending moment) rating as an 11-mil rail, but it’s about 100 pounds lighter. Standard cast aluminum crossmembers provide additional weight savings without sacrificing strength or durability, DTNA says.

With a standard 111.6" BBC, the 47X is well suited to regions or applications that require a...

With a standard 111.6" BBC, the 47X is well suited to regions or applications that require a shorter overall vehicle length, such as drywall trucks, and for those that need to meet federal or local bridge law requirements. An optional 110.8" BBC stup is available for mixers or super dumps.

Photo: Western Star

Such frame choices position the 47X well for weight-focused applications such as vocational tractors or mixers.

“We wanted to have the premier mixer truck in the industry, and we know with mixers weight is more of a priority than power,” Parlier said. “So, we focused on building a truck that hits 16,100 pounds for the mixer market.”

New Tools for Upfitters

Designing and assembling vocational trucks is a complex process, so DTNA has pulled much of this challenge into the design process. Engineers work directly with leading truck equipment manufacturers (TEMs) to get the build details right before the truck hits the assembly line, where errors are expensive and time-consuming to correct.

Parlier says it can take up to an hour to drill a single hole in a frame, so DTNA’s engineering teams work directly with the TEMs to get all of the holes pre-punched before the truck is built so they can literally just drop the body onto the truck and bolt it down.

DTNA says the Western Start 47X in mixer configuration weighs in a just 16,100 pounds in some...

DTNA says the Western Start 47X in mixer configuration weighs in a just 16,100 pounds in some instances. 

Photo: Western Star

Designers also use a frame-space configurator tool to prevent errors at the manufacturing stage such as placing a hydraulic tank where an outrigger is supposed to go. The configurator fills in the “blank” spaces on the frame, notifying the assemblers that that that space is already spoken for.

“That’s not necessarily a feature of the truck, but it's all automated through the ordering system and the engineering system,” Parlier says. “It was a big investment on our part, and the result is the truck that the bodybuilder needs when it shows up.”

The QuickFit Interface System is another feature pulled from the 49X. It offers ready access to the truck’s electrical architecture using and advanced multiplexed electrical system designed for easy TEM interface, programming and access to power. Connectors are located on the back of the cab, while the electronic control units are stored in the cab in the new dash electronic vault or back-of-cab E-Vault for easy access. Upfitters no longer need to drill into the back of the cab or through the floor. The interface is right at the back of the cab.

Traditionally, upfitters has used the space between the seats to mount driver control interfaces for their various bit of equipment. To keep that space free and to ease installation, DTNA has developed the Flex Panel – a panel that fits into the dashboard B-panel equipped with the appropriate control devices.

A proprietary FlexPanel provides TEMs the space and flexibility to easily integrate body...

A proprietary FlexPanel provides TEMs the space and flexibility to easily integrate body controls, freeing up space between the driver and passenger seats

Photo: Western Star

The panel would be pre-configured by the TEM and connected to the RP 1226 connectors already in place in the under the panel. The Flex Panel can also be configured with additional gauges, switches, an ELD mount or a RAM Mount prep, depending on customer needs.

“This whole system is designed to be designed to be plug and play, directly into the truck system so that upfit is a breeze,” Parlier says. “Upfitters can have their harnesses, all ready to go, then they can use the CHEC tool to get right into the parameter logic and design logic of the truck.”

Western Star’s CHEC Tool is the interface to the programmable controllers found on X-Series trucks. It enables TEMs and dealers to view and modify electrical configurations, giving them the power to customize inputs and outputs and change parameters within minutes. With the power of QuickFit and CHEC, what was once considered to be complex, expensive or impossible to do can be accomplished more easily and efficiently, DTNA says.

Cab and Body

The X-Series steel-reinforced aluminum cab is said to be 8% lighter while providing 13% more space than competitors, DTNA officials said. The cab structure has steel reinforcement in critical areas such as the backwall header, and the A- and B-pillars. The door hinges are reinforced, and were tested under conditions designed to simulate 15 years of use. The doors are built from galvanized steel and hem-sealed for corrosion resistance. All of the exterior metal brightwork is chrome or stainless steel, not chromed plastic.  

The X-Series cab suspension features vocationally tuned cab isolators designed for optimal cab stability.

X-Series cabs have composite roofs with a lowered, or trenched, center section optimized packaging of over-cab equipment without sacrificing interior headroom or door opening height.

Western Star will offer the 47X with a twin-steer prep package for export to Canada.

Western Star will offer the 47X with a twin-steer prep package for export to Canada.

Photo: Western Star

The cab has a one-piece roped-in windshield for faster repair times and optional single or high-visibility three-piece rear windows. X-Series windshields are 28% larger than previous versions, and they use 24-inch wiper blades that cross over the center of the glass, providing a 37% improved windshield wiper zone, according to DTNA.

All X-Series models come standard with a wrap-around dash that provides easy access to the driver command center and B-panel. There’s a multi-function steering wheel, and the new instrument cluster features Daimler’s Driver Command Center.

The truck’s interior also includes upscale appointments such as premium seating, premium insulation for greater quiet and temperature control.  

Three sleeper configurations are available on the 47X: 36-inch trench-style low roof, and 36- or 48-inch mid roof.

Three sleeper configurations are available on the 47X: 36-inch trench-style low roof, and 36- or...

Three sleeper configurations are available on the 47X: 36-inch trench-style low roof, and 36- or 48-inch mid roof.

Photo: Western Star

The 47X’s hood offers forward visibility of 24.8 feet – an 11-inch improvement over the 49X – while its composite construction and ISO Tech suspension system resists bending and cracking by absorbing and dissipating vibrations from road inputs.

And all Western Star X-Series truck off the full suite of Detroit Assurance safety systems including: active brake assist, adaptive cruise control, side guard assist, tailgate warning, lane departure warning, automatic headlights/wipers and intelligent high beams, brake hold mode, traffic sign display and active speed intervention with Detroit engines, as well as Wabco OnGuard including collision mitigation and adaptive cruise control, optional with Cummins engines.

Powertrain and Drivetrain

The 47X comes standard with the Detroit DD13 Gen 5 engine, which features higher compression ratios and a new swirl piston design to further improve combustion and efficiency. A new feature called ThermoCoasting in the DD13 Gen 5 prevents aftertreatment cool-down while coasting or operating lightly loaded, which keeps the system at its optimum temperature and significantly reduce the need for parked regens.

For weight-sensitive applications, the Cummins L9 and X12 engines are available.

Optional front-engine power take-off (FEPTO) is offered on both Cummins engine offerings and the Detroit DD13 for applications like snowplows. Similarly, rectangular fuel tanks and a raised aftertreatment system mounting are offered with Cummins engines for better clearance for belly plows.

The 47X is also offered with the new DT12-V vocational transmission. It offers three mode applications: rock-free mode, off-road mode, and paver mode.

Available Options

Engines & Ratings  

Detroit DD13 Gen 5, 370-525 HP, 1,250-1,850 lb-ft

Cummins X12, 350-500 HP, 1450-1700 lb-ft

Cummins L9, 260-380 HP, 860-1,250 lb-ft


Detroit DT12-V AMT

Allison 3000 and 4000 series automatics

Eaton Fuller 10- 13- 18-speed; 8LL and 9ALL manuals

Eaton Ultrashift PLUS and Endurant AMT

Drive Axles

Detroit single 23,000 lbs

Detroit tandem 40,000-46,000 lbs

Dana tandem 46,000-50,000 lbs

Meritor single 21,000-30,000 lbs

Meritor tandem 40,000-58,000 lbs

Meritor tridem 69,000-78,000 lbs

Steer Axles

Detroit single 12,000-23,000 lbs

Meritor single 12,000-22,000 lbs

Detroit twin steer tandem 40,000 lbs

Front Suspensions

Flatleaf 14,600-23,000 lbs

Flatleaf (tandem) 40,000 lbs

Taperleaf 12,000-20,000 lbs

Taperleaf (tandem) 40,000 lbs

Rear Suspensions

AirLiner single 21,000-23,000 lbs

AirLiner tandem 40,000- 46,000 lbs

AirLiner tridem 69,000 lbs

Chalmers tandem 40,000-70,000 lbs

Flatleaf single 23,000-30,000 lbs

Hendrickson tandem 40,000-70,000 lbs

Neway single 26,000 lbs

Neway tandem 46,000-52,000 lbs

Neway tridem 69,000-78,000 lbs

TufTrac tandem 40,000-52,000 lbs

Pusher & Tag Axles

Steer and non-steer 8,000-25,000 lbs

The 47X is scheduled to go into production in the first quarter of 2022. Customers can expect deliveries sometime later in the year. Despite the current supply chain challenges, Parlier says production for the 47X has been in the planning stages for some time. She doesn’t expect those issue to have a huge impact on deliveries of the truck.

“We are not immune from all that stuff, I'm afraid, but it kind of comes back to one of the benefits of the X Series platform. There's so much shared across the two that we've been able to plan around that,” she says. “We've been planning on the 47X coming into production in the first quarter of 2022 for a long time, and we great supply chain management teams that are doing everything they can to navigate that.”

About the author
Jim Park

Jim Park

Equipment Editor

A truck driver and owner-operator for 20 years before becoming a trucking journalist, Jim Park maintains his commercial driver’s license and brings a real-world perspective to Test Drives, as well as to features about equipment spec’ing and trends, maintenance and drivers. His On the Spot videos bring a new dimension to his trucking reporting. And he's the primary host of the HDT Talks Trucking videocast/podcast.

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