Workhorse Custom Chassis has enhanced its diesel options for commercial walk-in trucks. Beginning in August, the new four-cylinder Cummins ISB 4 electronic diesel engine will be available on Workhorse P Series commercial chassis with 10,000-, 12,000-, and 14,100-lb GVWRs. The engine, coupled with the Allison 1000 Series transmission, is designed to meet needs of walk-in truck fleets.
Workhorse chassis GVWRs range from 8,600 to 16,000 pounds, and use GM and Cummins powertrains with gasoline or diesel options. Chassis wheelbases range from 110" to 178" and include independent coil or I-beam front axles, depending on the model.
The new Cummins ISB 4 engine is the latest improvement to its four-cylinder engine lineup. The ISB 4 offers 170 horsepower and 420 ft-lb of torque.
The engine's performance is aided by its high-pressure common rail system that maintains high injection pressures regardless of engine rpm while also optimizing fuel economy and reducing emissions. Electronic controls provide multiple injection capacity, with pilot injection for cold-starting and noise reduction. The engine's 16-valve cylinder head is a free-breathing design that further enhances combustion. The rear gear train also improves performance and lessens noise by combining the cam, fuel pump and accessory drive into a rear mount. Overall, the engine achieves a 50% noise reduction from the previous model.
On top of this, the engine works with the automatic, five-speed overdrive Allison transmission. A 32-bit microprocessor facilitates engine and transmission communication to provide shifts with no power interruptions, whatever the road or load conditions. The transmission also features electronic diagnostics that identify problems before they turn into costly repairs.
Compared with the Cummins B3.9, the new ISB 4 engine cuts maintenance costs in half with its 15,000-mile service intervals.