Kenworth Program to Improve Fuel Economy

Kenworth program to improve fuel economy

After a refresh in 2017, Paccar in the US started a five-year Kenworth program to improve fuel economy and add features, technology and comfort to the early iteration of the T680 model. The result is the T680 Next Generation that was revealed early in 2021. 

Having driven the new Kenworth T680 Next Generation in a small press gathering at the Kenworth US Research and Development Centre, PowerTorque’s US Correspondent, Steve Sturgess, can say for certain it was worth the effort and worth the wait.

On hand for the 40-mile (64km), one-hour route, looping south and west of the Kenworth R & D centre, were two quite different derivatives of the Next Gen: a day-cab that likely will see use as a regional-haul prime mover and a top-of-the-line 76-inch sleeper model that has caught the attention of fleets and owner-operators alike judging from the order book. Those new trucks started to get into customer hands from April this year. Conversations at the driving exercise indicate to me it will eventually head for Australia.

Kenworth program to improve fuel economy

Walking up to the trucks, the aerodynamic modifications are quite apparent. There’s a new hood with an eight-inch narrower grille to better cut into the wind, the fenders feature gap closers to tighten the fit over the wheels to keep air from getting under the truck. The bumper extends down for the same reason and the side skirts extend all the way down with only inches to the road surface. The lower part of the skirts is in a flexible material to avoid road damage. Cab side extenders have been lengthened and, because they close the trailer gap, the left side extender is hinged to give access to the deck plate behind the cab. There’s also a tandem fairing and attractive, polished wheel discs in the full aero package.

Keeping the air close to the truck is the name of the game and new corner ’turners’ are fitted to the A pillars beside the windshield edges. Under-bonnet air is streamlined and there are outlets at the back of the fenders to exhaust any trapped air out to fill in the air streaming down the sides of the truck.

Both trucks were equipped with the 405hp MX13, 13-litre Paccar engine backed up by the automated Paccar 12-speed transmission. As the T680 is designed to feature a down-speeded powertrain, drive axles had a 2.64 to one ratio. This puts the torque peak of 2373Nm (1750 lb-ft) flat between 1100 and 1400 rpm. The engines’ speed range is from 1000 rpm to a maximum of 1500, but the green band on the new electronic tachometer in the glass dashboard between 1125 and 1400 rpm and contributes to the 6 per cent fuel savings over the current T680.

Kenworth program to improve fuel economy

The glass digital dash is one of the stand-out features of the new model. At 15 inches it clearly displays a wealth of information which can be customised by the driver for both content and complexity. The test trucks had the standard configuration of gauges and supplementary info such as time and outside temperature as well as a fuel economy gauge and readout for the Kenworth program to improve fuel economy. 

One particularly useful feature is an icon that gives the current speed limit as you drive, useful in the mixture of urban, divided highway and Interstates of the test route. The speedometer is digital within the conventional round tach and ribbon indicators display the supplementary gauges. But this just hints at the capability of the new dash. 

Kenworth program to improve fuel economy