DAF’s automatics for the people
Paccar subsidiary DAF has refreshed its LF lightweight truck range with new Cummins-built engines and fully-automatic ZF PowerLine torque-convertor transmissions. Fuel savings of up to seven per cent are promised, and there are weight-savings too.
The trucks use the next-generation of Cummins-built, Paccar-branded PX-5 (4.5-litre four-cylinder) and PX-7 (6.7-litre six-cylinder) engines, which feature a lightweight compacted graphite iron block and cast-iron cylinder-head. New low-friction pistons are specified and waste-gated turbochargers are fitted.
Power output options for the four-pot engine are 170, 190 and 210 hp, with peak torques ranging from 700 to 800 Nm. Six-cylinder outputs are 230, 260, 290 and 310 hp, with peak torques from 900 to 1200 Nm.
The change to a fully-automatic transmission is arguably even more significant than the engine upgrades. Previously, DAF offered a five-speed Eaton manual on its lightweight LF City, and ZF’s EcoLite six-speed manual across the rest of the range, with the option of the nine-speed wide-ratio EcoMid from 18-tonnes up. An automated-manual version of the EcoLite was also available.
ZF launched the PowerLine in Europe last year as a truck and coach gearbox with torque capacity of up to 1,355 Nm. It has an eight-speed planetary geartrain, compared to the rival automatic Allison’s six speeds. ZF claims this gives it faster shifts than the competition and the greater ratio spread could make fuel-savings of 10 per cent. It can be fitted with engine-speed PTOs at the three and nine o’clock positions.
Advanced control enables it to skip-shift when necessary, and the non-wearing torque converter is bypassed early by a lock-up clutch.
Long fluid-change intervals and an oil filter that lasts the life of the transmission will further reduce cost, according to ZF.
According to DAF, the automatic’s: “Ability to shift ratios without torque interruption enables smooth shifts and quick throttle response, resulting in excellent comfort and driveability. In addition, the new transmissions provide outstanding low speed manoeuvrability, enabled by an ‘urge-to-move’ feature upon releasing the brake pedal.”
DAF said it had changed final-drive ratios to accommodate the new transmissions, and the established manual gearboxes would still be offered. The Allison transmission, a standard fitment for many users is the fire and municipal sectors, remains on the options list.
The PX-5 engine is 15 kg lighter than its predecessor, while the PX-7 saves 8 kg.
Compared to the previous ZF six-speed transmission, the Powerline saves 34 kg, while about 90 kg is saved if it is fitted in place of the Allison.
The old LF City model (with a 4.3-litre Chinese-made Cummins engine) has been dropped.
Phil Moon, marketing manager at DAF Trucks, told Transport Operator: “I believe the new PowerLine gearbox brings a level of performance which will accelerate the shift away from manual gearboxes in medium weight trucks. It’s obviously already happened in passenger cars and tractor units, but we have still seen a lot of operators who buy two-axle rigid trucks attracted by the simplicity of a manual gearbox and the impression that a manual gives the driver more control and can be more responsive in traffic.
“The PowerLine drives like an automatic – indeed it has a torque convertor but delivers even better fuel economy than a manual. And the ‘urge-to-move’ feature and swift seamless gearchanges make it very easy and comfortable to drive.”
Production of the new trucks has already commenced.
