Coming to a dealer near you, the reinvigorated Daf XF
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By David Wilcox DAF TRUCKS HAS refreshed its range-topping XF105, seven years after it was introduced.
The new model, called simply XF, goes into production next spring and will be available only with Euro-6 engines.
The new XF will not come cheap: list prices are about €14,000 (£11,258) more than the current model, but that includes vehicle stability control – currently an option – and a driveline warranty increased from two to three years.
Although the new model is recognisably an XF, there are major changes underneath. Much has been driven by a 30% increase in radiator surface area to cope with the heat rejection from the new engine’s EGR system, and the aim to cut cooling-fan engagement time by 50%, saving parasitic losses.
The radiator is marginally taller but much wider, so Daf has opted for a new chassis with main rails laring outwards at the front. This allows the track to be pushed out by 50mm to suit the full 2.55m width limit. There is a new standard 8-tonne front axle with widerset, two-leaf suspension.
The rear axle is also new and boasts a new four-bag air suspension and an anti-roll bar integrated with the locating links. This saves about 60kg. Daf said the XF will be no more than 90kg heavier than the current model, despite almost 250kg of Euro-6 emissions kit.
The Euro-6 MX13 engine in the new XF is a development of the current 12.9-litre MX introduced eight years ago. It still features a side-mounted camshaft but unit pump fuel injectors have been jettisoned in favour of Delphi’s F2P common-rail system with two camshaft driven two pumps pressurising the fuel rail. Maximum fuelinjection pressures are up from 2,000 bar to 2,500 bar.
EGR has been added to work in conjunction with SCR exhaust after-treatment to hit the ultra-low Euro-6 NOx limit. A Holset variable geometry turbocharger with an electronically controlled actuator improves engine transient response and helps drive EGR. When required, a seventh injector will spray fuel into the exhaust ahead of the particulate ilter, raising exhaust temperature if it is too low to burn the soot in the ilter.
AdBlue consumption is likely to be 3%-4% of fuel consumption. Daf forecasts that fuel consumption will be as good as ATe variants of the current model.
Power and torque ratings are unchanged from Euro-5: 410hp/ 2,000Nm; 460hp/2,300Nm; 510hp/ 2,500Nm.
For the moment, Daf is sticking with the ZF’s AS-Tronic 12-speed automated gearbox rather than moving up to its successor, the TraXon (CM 19 July). However, the control software now includes an eco-roll function for downhill running with the drivetrain disengaged, better slow-speed manoeuvring and a much swifter shift between 12th and 11th gears to
minimise loss of momentum on uphill gradients.
A new, ultra-long rear-axle ratio of 2.38:1 will be offered, in keeping with the move towards enginedown-speeding.
Underneath the new panels, the cab-shell is unchanged and can be traced back to 1987, making it the oldest cab-shell among the mainstream European units. The cab sits 35mm higher but the engine cover is still 150mm high, and internal headroom is unchanged.
The interior of the XF is essentially a refreshed version of the XF105, with some new interior trims and materials. The most signiicant changes are new seats and redesigned instrument display.