With its enviable record of wearing the metaphorical yellow jersey
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for sector-leading sales in the UK, Dal's LF45 7.5-tonner is hardly a novelty on our roads. However, some aspects of the yellow truck tested here make it something of a rarity. if only because of their newness.
For a start, its EEV (Enhanced Environment-friendly Vehicle) engine makes it probably the cleanest dieselpowered truck on the road. It also features one of the first applications of ZF's new automated transmission for light trucks.
EEVs were brought to us in 1999 by EC Directive 1999/96/EC, primarily as a standard for natural gas engines, particularly for public transport. It was never anticipated that diesel engines would be able to meet the stringent targets, but such has been the progress made in the past few years that Daf's latest FR four-cylinder 4,5-litre engine easily beats the EEV standard in every respect. and in the case of carbon monoxide (CO) and hydrocarbon (HC) emissions, by a huge amount, without having to use a soot filter (see panel, page 37).
The FR engine with Euro-5 and EEV is currently only available at the middle 158hp/600Nm rating, flanked by 138hp/550Nm and 182hp/700Nm Euro-4 versions. The LF range also has a selection of 6,7-litre six-pots but they're not really recommended for a payload-conscious 7.5-tonner.
It has always slightly baffled us as to why so much of the early development of automated manual transmissions was directed towards heavy trucks, most of which are on long-distance work, where a gear change is rarely seen. No doubt manufacturers will say it is easier to amortise the development costs in a heavier-duty, highercost application.
But what the industry is really crying out for is an
affordable auto suitable for light-to-middleweight urban delivery trucks, which frequently experience hundreds of changes per shift, and in an environment where driver concentration is at a premium. In theory, the ZF AS-Tronic Lite is the answer to a distribution driver's prayer.
So with the EEV engine and baby ZF, this is the test truck. The rest of the spec is familiar from previous tests. It came with a 20ft box body from Bevan, which featured a slight aerodynamic slope at the rear. If, as we do. you count the basic price as including the driveline options. the test truck still had another eight grand's worth of extras, with the most significant being cab aerodynamics, rear air suspension and air-con. Among the smaller items were the 1380 driver's air bag and the £360 anti-idling control.
One more small point, however — this is the first 7.5tonner to run around our Welsh distribution vehicle route with the benefit of a speed limiter. We were mighty keen to find out just how much difference motorway running 14mph more slowly would make. The average fuel consumption for 7.5-tonne boxvans over the last six years is 16.9mpg, although a Euro-3 Mercedes-Benz Vario still shows the benefit of integral bodywork with 22.9mpg.
On the road Operating the new baby ZF is simplicity itself. The main control is located just where a conventional gearstick would come through the floor, the rotary knob familiar from the larger Daf ZF AS-Tronic installations, with D and a tortoise clockwise from N. and R and another tortoise anti-clock.
Behind this are two rocker switches, one for manual and auto modes, and the other to shift up or down in manual mode. Some kind of column or steering wheel control might be more ergonomic for extended manual operation but — as you will read — there's little benefit from using manual, so it's hardly an issue. More of an issue is the parking brake location behind the driver's left elbow, requiring a minor bit of contortionism, and made more significant by the fact that Hill Hold is not available.
The change is occasionally a bit clunky from first to second, but after that, every shift is smooth and jerk-free. On the Daf, the ZF box is well matched to the engine characteristics. It holds on well to gears right down to 1,000rpm under light load, and on the occasions when more power is needed, the kickdown moves the shift points up the scale, but in reality it's rarely used. At 80km/ h, the engine is turning at 1,680rpm. just below the top of the 1200-1,700rpm torque plateau.
Considering how clean it is, the I58hp EEV engine's performance is a revelation. Standstill to 80km/h takes 27.8 seconds, on the right side of the sector benchmark, hut it's the mid-range figures that particularly impress. The engine feels strong and the clock agrees, with figures that wouldn't disgrace a 3.5-tonner.
One area that even impressed Daf road test supremo Richard Kingston was the hill-start ability. The 1-in-4 test bill at the Chobham proving ground frequently beats the distribution sector trucks that we test there, but the Daf romped away on the 1-in-3 slope in D mode without a hint of drama. In tortoise — or low-speed manoeuvring — mode it did its job as intended, the level of fine control being noticeably better than in D where there was a slight tendency for unintended coasting at walking pace.
Still at the proving ground, the emergency braking test was completely drama-free, although in true Daf tradition, the foot pedal was rather lacking in feel (although considerably better than the old CF/XF item). The LF45 comes with an exhaust brake as standard, conveniently operated by a button on the multi-function steering wheel. And unlike many of its ilk, it works well enough to be a useful tool in ordinary driving even without entering the Blue sector which runs to a rather high 3,200rpm. With the exhaust brake switched on, the microchips work out that if you then touch the brake pedal, you need more braking and change down for you to maximise retardation.
No doubt helped by the optional electronic air suspension on the rear, the ride proved better than the norm situations, while no handling vices were apparent from the occasional rub of the low mudflaps on tighter corners.
Productivity We've established that the Daf LF45 EEV is as clean as diesel power gets at the moment, but at what price? In upfront capital costs, it's the samell ,100 as the Euro-5 option. so that bit is a no-brainer, as youngsters say. As mentioned above, it's too soon to say how the Daf's figures stack up in the grand scheme. Although there are a few 7.5-tonne rivals in the wings nearly ready to test, we suspect that the Daf's overall 21.5mpg will be a benchmark that will take some beating. Compared with the previous 16.9mpg sector average, it certainly proves the potential fuel benefits of the newly limited top speed. Obviously, the bulk of the savings were from the motorway section. where the 22.4mpg is at least 5.0mpg better than a good truck would have returned cruising at 70mph. AdBlue was drunk at what's becoming the norm, at 4.8% of diesel.
Fuel aside, there's the question of the automated transmission. At £2,130, it represents a huge saving over the Allison alternative and has no efficiency penalty over a synchromesh manual. The residual valuation experts are certainly not prepared to penalise the Daf auto in their predictions, and reckon that in a few years time, it will retain a significant amount of the extra outlay. As you'd expect from such a popular vehicle, there are no nasty surprises in any of the other running costs.
Sadly, the only downside is that the Government seems unaware of the environmental benefits of what is surely the first of many ultra-clean diesels and currently offers no real incentive to utilise those benefits.
The little IS day cab is not the most spacious, but access through wide-opening doors won't hinder even the busiest multi-drop driver. The £770 luxury air driving seat is probably a luxury that not too many drivers will experience, but nice all the same. However even in the basic passenger seat, the ride never gets uncomfortable.
Cross cab access is easy. unless you use the central footwell area to stash an overnight bag as there's no room behind the seats for more than a briefcase. Between the seats is the only lockable facility, a bin-cum-tray which incorporates a couple of dual-sized drinks holders. There are two substantial coat-hooks and an elasticated net on the rear wall, as well as a couple of handy net-fronted bins across two thirds of the over-screen space, The remainder is used by a block of four DIN audio bays and a few switch blanks.
At the wheel, the view of the car-like dash is dominated by the fully adjustable multi-function wheel, phone and exhaust brake controls on the left and cruise and speed limiter on the right. The smart looking dash is fully kitted, including the new AdBlue gauge.
A new option is the Bluetooth telephone module which just slots into a standard Daf mobile phone mount, and talks through a remarkably clear speaker unit in one of those DIN fixtures.
Six good mirrors provide excellent views of the cab front and sides without seriously impeding outward vision. There are three internal visors across the front, but none above the driver's door, and one rather noisy transparent external one.
The effect on this of a strong headwind at the proving ground prevented meaningful noise readings from being taken.
However, from the tickover figure and subjective impressions on the road, while far from noisy, the Daf is not going to set any records. An annoying whistle from the heater vents didn't help, and while on the subject, the central vents are mounted a bit far away from any driver who likes roughly equal amounts of fresh air from each direction. •