Wind of change
Aerodynamic truck gives Kenworth a fuel-saving advantage
KENWORTH has developed the ultimate aerodynamic truck and trailer combination. The T680 Advantage package of wind-cheating and fuel-saving improvements are all now available in the US.
The T680 is not built in right-hand-drive but some of its technology, including components from the Advantage trucks, could soon make their way here.
The T680’s aerodynamic design includes a sloping roof that pushes air up and over the trailer. The Trailer Nose addon reduces the gap between the front of the trailer and the back of the cab to minimise the effect of crosswinds.
A cut-out still enables the driver to swap trailers.
Side skirts fitted to the prime mover conceal the fuel and AdBlue tanks to create a smooth airflow down the side of the truck. The trailer also has side skirts and all wheels have disc covers to reduce drag.
The most obvious aero change is the ATDynamics Trailer Tail. This odd-looking addition, often referred to as a duck tail, has been found to deliver an impressive fuel saving of 6 per cent.
From the side, it looks as if the trailer doors have been left open— but its side panels point inwards, the roof panel slopes down and the lower panel faces up. The tapered tail helps improve the airflow by breaking up the low-pressure zone at the rear of the trailer and the hinged panels fold out of the way for loading and unloading.
The regulation covering the maximum length of truck and trailer could affect the set-up being adopted in Australia— a Trailer Tail would effectively reduce space for freight.
Kenworth fitted the Advantage truck with wide single wheels and tyres on all but the steering axle, in place of two narrower tyres, as a further weight and fuel saving strategy.
The truck is a 6x2, instead of 6x4. The prime mover’s rear axle is not driven to save weight and reduce the load on the engine.
One item on the Advantage truck that is starting to appear in Australia is the Idle Management System. Rather than being a stop-start set-up that kills the engine instead of idling at lights, it is a batterypowered climate control system so that drivers can avoid the noisy and inefficient practice of idling to run the cab climate control systems.
The IMS is basically a split system— like those used in a house— but can run off four regular batteries and features on-board diagnostics to monitor power levels. Kenworth claims it can save fleet operators as much as $7500 a year per truck.
Tyre pressure monitors ensure inflation for the least rolling resistance.
The Advantage runs the latest Paccar MX13 engine, which is expected to be available soon in Australian Kenworths, linked to an Eaton UltraShift Plus automated manual transmission.
The engine software encourages the driver to change up to the next gear by limiting power at certain revs. A built-in limiter keeps the truck from running at less efficient speeds.
Meanwhile, aerodynamic cab and trailer extensions are set to become more popular in Europe. The European Commission will change transport regulations to allow for more rounded cabins and duck tails.
The current maximum length of trucks and trailers in Europe is 18.75m, which means cab-over trucks are the primemovers of choice.
The EC recognises that longer combinations with aero cabs and sleeker trailers could cut fuel consumption and emissions by up to 10 per cent.
Swoopy styling: Wind-cheating add-ons include wheel covers, side skirts and ‘duck tail’