ROADTEST DAF FA 1900
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Indeed the 6.2-litre engine is so quiet that Daf does not even need to fit side baffles to meet the drive-by noise standards.
It is ironic that our test of the FA 1900 with the time-served 220 cab appears in the week that the new 95 Series with the Daf/Enasa Cabtec cab is announced. Many of the criticisms of the 220 cab will, no doubt, be answered by the new cab — but it seems it will be some time before a derivative of the Cabtec unit appears on vehicles as far down the line as the 1900.
• BRAKING
Compared with the light, 13kg effort needed to operate the clutch, the treadletype brake pedal feels heavy, but braking control and performance with ABS are excellent.
On a dry MIRA track immediate response to full pedal movement gave a peak deceleration in excess of 0.8g from 64km/h with no trace of wheel lock.
The system is designed to operate at a higher-than-normal pressure. Our Motometer charts show a deceleration trace that wavers slightly throughout the stop as the ABS anti-lock system controls the rate at which each wheel is slowed to bring the vehicle to a halt. In the driving seat the ABS control is almost undetectable except for that excellent straight-line braking and an ability to steer even during emergency stops.
• HILL PERFORMANCE
According to the specification sheet the FA 1900 has a maximum greadeability of 21% (1-in-4.8) — but we were unable to restart on MIRA's 20% (1-in-5) test slope. On the first attempt the gradient proved to be more than the clutch could manage. After we had given the friction material time to cool down we tried again, this time feeding the clutch in more gradually. The vehicle did begin to move forward, but within a couple of metres the gradient reduced the engine speed down to a stall. Finally, using the lowest (7.43:1) ratio, the vehicle was able to restart and climb the 16% (1-in-6) test hill. It needs a lower first gear.
Six gear ratios and a high power-toweight ratio of 9.59kW/tonne provide the 1900 with a top speed of 108km/h. The lively performance of the 16-tonner was reflected by good journey times around our test route despite heavy traffic at Hereford and Cirencester.
Both timed hill climbs, at Monmouth and at Wantage, were exceptionally quick but we have reservations about the number and the spacing of gear ratios in the ZF S6-36 gearbox. The three lowest gears are closely spaced and then there is a large gap between third and fourth. Only by taking engine revs to the red line at 2,600rpm is it possible to drop into the next gear at about 1,500rpm — where it is some 100rpm below maximum torque.
If engine speed is restricted to the green segment of the rev counter, at 2,200rpm, the next gear is selected at about 1,000-1,100rpm: well below maximum torque. Gear changes from fourth to fifth can be made at 2,200rpm and from fifth to sixth as low as 2,000rpm.
When hill climbing, the first three ratios are much too close together, while the gap between third and fourth is much too large for gear changes to be made before the torque curve begins to drop away.
As fourth gear pulls well down to a road speed of about 35km/h it could be argued that the top three ratios, which are more equally spaced, are quite adequate for the the majority of road use.
• FUEL CONSUMPTION
The fuel consumption figures seem to reflect this, for the Daf 1900 set a new record consumption around our 338km Welsh route. Motorway and A road returns of 22.51it/1001an were identical, but the A road figures may have been affected by traffic delays at the two major towns on the route.
This performance is all the more creditable when compared with the next best fuel return, put up by a Seddon Atkinson 2-11 which had the added advantage of a platform body.
Once again this shows that more power does not necessarily lead to an increased use of fuel, even on what is considered to be a relatively high-revving engine.
• HANDLING
The big cab contributes to the vehicle's 'big-truck' feel, but steering is not heavy. The ECAS rear suspension gives a level, comfortable ride as well as counteracting body roll. After gentle braking it is occa sionally possible to feel the system compensating for the compression of the front suspension.
A high purchase price reflects the high specification. The cost of the optional small (200 litre) fuel tank does seem excessive, but no extra charge is levied if the vehicle is originally specified with the tank and it is fitted on line. Even so, £195 for labour costs is still expensive.
• SUMMARY
Dais powerful 1900 4x2 rigid is ready for re-certification, which will be required of all vehicles operated before next April for 17-tonne operation. The Dip will begin inspection and offer post-dated paperwork from February so operators will be able to use increased payloads from day one.
The turbocharged and charge-cooled DNS 6.2-litre engine coupled to a sixspeed gearbox returned 22.5kt/1001cm, the best fuel consumption so far obtained around our test route at 16.26 tonnes.
The DAF 1900 pulls well, has a lively performance and gave average journey times round our test route despite some adverse traffic conditions. An eight-speed box with a more even gear ratio spread might result in a general improvement in performance if it were fitted in place of the six speed unit which is specified to save weight and cost. It could also improve the 1900's restart capability with a lower first gear, which will be sorely needed at 17 tonnes.
ECAS provides a considerate ride for load and driver alike. Its remotecontrolled height adjustment will allow compatability between the load platform and a wide range of dock heights.
Anti-lock brakes are more important for articulated and drawbar outfits than for solo rigid vehicles, but the ABS system allows an impressive standard of braking.
Dais revamped cab is a comfortable and quiet working environment, and the DNS 6.2-litre engine provides the high level of power that makes this big 16tonner such an easy vehicle to drive. When the weight limit goes up to 17 tonnes the FA 1900 will be able to offer more than the basic 10.16-tonne payload that so many operators seem to require from a maximum-weight two-axle rigid.
by Bill Brock