Revival in construction activity is driving healthy sales of vocational trucks, a recently launched highway tractor has become a “home run,” and interest in natural gas power should cause that segment to grow to 15-20% of heavy truck sales by 2020, Kenworth Truck representatives said at a briefing for reporters Friday morning.

Road building, in particular, is resulting in brisk sales of Kenworth’s T800 and T880 models, with the newer and more modern 880 now accounting for 40% of vocational-model production at the main plant in Chillicothe, Ohio, where reporters assembled for a ride-and-drive event. Also helping is home building, though it’s not regained the strength it had before the Great Recession.

Option content on the T880 now covers 85% of all vocational applications, said Alan Fennimore, manager for that segment within KW’s sales and marketing departments. More options coming include a front-engine power take-off and a wide-hood version with a larger radiator for low-speed heavy-haul operations.

The older “T8,” which entered Kenworth’s lineup 27 years ago and does a variety of vocational and on-highway jobs, will probably stay around for another five or six years simply because “some guys like the T800,” Fennimore said. Conversions are made “when others get in the T880 and look around and say, ‘Wow,’  and they just love it.” Changes are being made in the Chillicothe plant to build more T880s.

The T680 road tractor that was introduced about a year ago now accounts for half of all sales in that segment, said Brett Vanvoorhis, on-highway marketing manager. About 18,000 have been sold as buyers switch from the older T660 because of the 680’s greater room, comfort and technical advancements.

Like the T880, the T680 uses a cab that’s longer, wider and quieter than the cab on older models. It’s 2.1 meters (82.7 inches) wide, about 8 inches more than the narrow cab on the T660 and other older Kenworths.

Aside from extra interior room, the wider cab covers the entire front of a cabinet that houses tanks for compressed natural gas, said Andy Douglas, national sales manager for specialty vehicles. Behind a narrower cab, a CNG cabinet sticks out to where he and others call it a “flying mattress.” Now the aerodynamics of the T680’s nose and cab are extended past the CNG cabinet, adding a bit of fuel economy.

“I’m a true believer” in natural gas, Douglas declared. “It’s no longer a science experiment. It’s happening. The question is not if, but when” it will become popular. “Eighty years ago, diesel was the alternative fuel. It took 25 years for it to become common” as truckers converted from gasoline engines.

Early adopters of gas were operators of transit buses, then refuse trucks, which stay close to fueling points, he said. Also, “they had an engine, the 9-liter” ISL G from Cummins Westport.  Now operators of concrete mixer trucks are beginning to buy, and on-road operators are being pushed into gas by shippers who want sustainability and a “green” image. Cummins Westport’s ISX12 G is the enabling engine for viable operation of 80,000-pound tractor-trailers.

“But I’m telling everybody who will listen to me at Cummins to build the 15-liter” gas engine that Cummins recently put on “pause” due to uncertainty for gas-truck prospects. The 15-liter is needed for use in over-100,000-pound combinations here and in Canada, he said, adding that the engine builder is now considering it again.

The cost advantage of gas motor fuel – about $1.50 to $2 per diesel gallon equivalent -- alone makes the case for natural gas, Douglas said, so fleets really don’t need government subsidies to make it financially attractive. The 15% to 20% market share for gas by the year 2020 is one he’s heard, so he’s not predicting it.

As for gas types, the lower cost of compressed natural gas and equipment to store and burn it is why CNG takes 90% of NG truck sales. And there are almost 700 commercial CNG stations in the U.S. compared to 56 for LNG. However, there are 90,000 diesel filling stations, “including one near you.”

“Kenworth is very committed to diesel,” he said. “By no means do we say that diesel is going away. We’ve invested a tremendous amount of money in diesel,” with the Paccar 12.9-liter MX-13 engine as a prime example.

More money is being invested in an additional product, a 10.8-liter MX-11 that’s due out next year, said Alan Fennimore, the vocational segment manager. It will be ideal for mixer trucks and bulk haulers who can convert the MX-11’s 300-pound weight savings over the MX-13 into payload.