Kenworth T800: History, Specs, Hoods and How to Identify One

From the T600's Nose to a Vocational Workhorse

The story starts with the T600. Introduced for 1985, it was the first semi-tractor to bring an aerodynamic design, sloped hood included, to production, and it needed a set-back front axle to make that hood and its larger bumper work. Kenworth then spun that idea into a family of sloped-hood trucks, and the heavy-duty member was the T800, introduced in 1986. Some references give 1987 as the first model year, which is why both dates turn up.

Where the T600 was aimed at highway fuel economy, the T800 went to work. Kenworth lists it as its vocational and severe-duty truck, sold either as a tractor or as a rigid straight truck. By its 25th anniversary in 2011, about 235,000 T800s had been sold, and Kenworth estimated roughly 80 percent of them were still on the road. That year's test trucks show the range: a dump truck with a 485 hp PACCAR MX and an Allison 4500 RDS automatic, and a heavy-hauler with a 565 hp Cummins ISX, an Eaton UltraShift Plus and a rating of 140,000 lb with permits.

Set-Back Axle, Set-Forward Cousin

The T800 is a set-back front axle truck. Moving the steer axle rearward is credited with better visibility, maneuverability, turning radius and ride, all things that matter when backing a dump body into a tight site.

Buyers who wanted the sloped hood with the axle out front had another option. The W900S, introduced in 1987, adopted the T800's sloped hood but paired it with a set-forward front axle and a raised chassis. It looks much like a T800 at a glance, and the axle position is the quickest way to tell them apart. Kenworth ended W900S production in 2020 and pointed customers to the W990 and the T880S, the set-forward version of the T880 that was previewed in 2016 and went into production in 2017 for mixer and dump work.

Wide Hood, Short Hood and Engines

The T800 was built in several hood forms. The wide-hood T800W was designed around large engines and extra cooling capacity, and Kenworth says operators favor it for specialized heavy haul, oilfield, logging and off-road work. In 2005 Kenworth added its Extended Day Cab and AeroCab sleepers, including the 38-inch AeroCab, as options on the wide hood, with its chief engineer noting that many oilfield, heavy-haul and construction customers ran the T800 in that form. At the other end sits a short-hood model, which Kenworth offered with a front engine power take-off for jobs like snowplows and dump trucks, raising the cab and hood 3 1/2 inches to clear the PTO shaft.

Engines changed with each round of emissions rules. For the 2010 emissions rules, Kenworth made the PACCAR MX, rated from 380 to 485 hp with up to 1,750 lb-ft, the lead engine for T800 and W900 mixer and dump models, with the Cummins ISX15 also offered and an ISX11.9 slated for the T800 later that year. These 2010-compliant engines use selective catalytic reduction and need diesel exhaust fluid.

T800 vs W900 vs T880

The W900 is the long-running flat-hood conventional, in production since 1961. The T800 shares its cab with the W900, Kenworth's 1.9-meter cab, so the difference sits ahead of the windshield: a squared, upright hood on the W900 and a sloped one on the T800. For more on the flat-nose truck, see our Kenworth W900 guide, and for the truck that started the slope, our T600 guide.

The T880 is the modern answer. Kenworth launched it at the Mid-America Trucking Show in 2013 with the 2.1-meter-wide stamped aluminum cab first used on the T680, aimed at dump, mixer, refuse and heavy-haul work, with the PACCAR MX-13 standard and the Cummins ISX15 optional. Kenworth described it as a complement to its vocational lineup, including the T800, rather than a replacement, but within six months orders for the T880 had overtaken the older truck.

How to Identify a T800 and Its Legacy

Start with the nose. A T800 has a hood that slopes down toward the bumper, unlike the upright hood of a W900. Then look at the front wheels: on a T800 the steer axle sits set back, while a W900S with a similar hood has it set forward and rides higher. A narrower cab than a T880 points to the older 1.9-meter cab. Hood swaps are common, though, because aftermarket fiberglass hoods are sold for different T800 years and styles, so check the VIN and build records before trusting the sheet metal.

The end of the line is in sight for part of the family. In March 2025 Kenworth announced it would end production of its legacy 1.9-meter cab trucks in 2026, naming the W900, the C500 and the wide-hood T800W, citing changing emissions rules and component constraints. It points T800W buyers toward the T880S with its Performance Hood, which takes the Cummins X15 at up to 605 hp and 2,050 lb-ft. The trucks already built will keep working for years, hauling dirt, logs and heavy iron.