A busy year, a mixed ba
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'HEN ASSESSING a past year's 3..avy vehicle road tests — for Jr purposes this means those ter 7.5 tonnes (7.38 tons) gvw we like to be able to draw mitive conclusions and make rect comparisons.
Manufacturers, when they rot a rival launching a new odel, may try to jump on the indwagon by getting us to test eir offering in that market segent, even though their model is been around for years. They st want operators to reember their product, while for ; it can be good news because ore often than not it's a vehicle e need to test or re-assess.
But this year the psychology oke down, and we ended up ith a completely mixed bag of hicles, from diverse weight Itegories and with power outits which covered the whole lectrum. Direct comparisons e mostly impossible.
However, we did manage a ick to back test of Leyland's mstructor and Seddon Atkinin's 300 8x4 tippers; and the )dge Commando and Scania 12M are equatable sixteen-tonors.
Tractive units figured promi nently in the test year, although our new Crane Fruehauf boxvan test trailer, which succeeded the flat at the beginning of the year, changed the profile of the rigs tested and precluded any comparison with those of previous' years.
And the introduction of the eight-hour day has changed our overnight stopping points (although the route remains the same) and thus the time of arrival at certain points. This last change probably does not materially affect our tests, although it could be argued that traffic flows are different, depending on the time of day. However, as all this year's tests were carried out with the same timings; they are all to the same standard.
The eight-hour day has made no difference to our mediumweight tests, as we can easily cover the Welsh route well within that time. One medium vehicle we had been after since its introduction and which finally came our way in November was the Bedford TL. Tim Blakemore took a 1260, 12.5-ton rigid round the route and found it a lot more comfortable than its TK stablemate.
Because the TL is the more upmarket of the two — it nevertheless shares the same mechanical components, model for model — it is the cab which features the most important differences. Vision to the front and sides is greatly improved on the tilt cab TL with 92mm (3.5in) more head room and a 133mm (5.25in) deeper screen. Corner windows give good side vision, a feature Tim found . useful at busy road junctions.
The TL's styling is similar to its predecessor's, but no cab panels are shared between the two models, says its maker.
The cab tilts manually through 50 degrees and the tilting process takes only a few seconds. The cab is easy to lift, but the preliminary release of the lock-down mechanism is a more lengthy affair. A ratchet spanner fits onto the squareheaded shaft of the lock-down clamp. The spanner is stowed in the cab in the vehicle's tool kit. Once this clamp has been released, a safety latch also has to be lifted before the cab can be tilted.
The dual passenger seat is standard and a Bostrom suspension seat for the driver is offered as an option.
The engine is mounted quite far back in the Bedford chassis and this helps to prevent engine noise instrusion into the cab.
While this "Blue Series" diesel engine is said to be the quietest ever produced by Bedford, interior noise levels are on the high side, probably because of the lack of noise insulation material on the underside of the cab floor. Our noise meter read ings taken at MIRA were 3dB(A) up on the Ford Citfig 1314 and Dodge Commando sixteen-tonner.
The useful and typically Bet ford wide shelf behind the sea is retained for the TL and don plemented by a shelf abovd header rail. One cab detail Bedford's engineers see have overlooked is the fact the clutch pedal is mounte high, leaving insufficient lei room between it and the Moe ing wheel.
Bedford's new gear leye though, has a neat integral tVVI speed-axle switch fitted into top. Similar in style to overdrh• switches used on light vans an cars, it is easy to use, but on th particular TL the shift itself i Eaton axle was sometim s little uncertain.
Like the 16-ton Dodge Qn mando 2 we tested, this Bedlfot had overall gearing which 4aN 5th low a lower ratio than '41 high, making for an untidy 'el step diagram, but it is unlike cause any problems for ittol drivers once they are awa the peculiarity.
The front road springs orth TL are unusually long tapere leaf ones, chosen to give a softt ride, unaffected by variatiorts i interleaf friction. The front lsui pension works well in isolairi the cab and driver from roa shocks. One of the 1982 model year pecification changes makes in?gral recirculating ball powerssisted steering standard on TL 260 models.
The Burman steering on our ?st vehicle gave a good degree f assistance and lacked any unertainty in straight-ahead posion. But this TL's turning circle as on the large side — a istinct disadvantage for an uran distribution vehicle.
Our TL 1260 was fitted with le naturally aspirated Blue enins, set at its lowest available ower rating of 95kW (128bhp). During our test the -Bedford ulled in 19.01 lit/100km I4.86mpg) at an average speed f 61.83km/h (38.46mph).
To sum up, we felt the TL ffered important improve-lents, particularly in the areas f driver comfort and ease of ervice and maintenance which hould be enough to lure most K operators to the TL.
SLIGHTLY higher up the weight scale — but only just — was the 13-ton Ford 1314 which we tried in October.
Over 210 miles of West Country and Welsh hill driving, the vehicle returned an exemplary consumption figure of 10.05 lit/100km (15.65mpg) while maintaining a journey time about average for the course.
The cab, larger than its predecessor, is claimed to be an aerodynamically superior design with its unusual flared collar at the rear.
Slightly staggered steps, placed in front of the wheel arch, make the short climb to the drive r' s seat quite safe and effortless, but a moulded grab handle at the end of the facia was neither obvious nor convenient, so the steering wheel became a substitute.
Exceptionally deep windows in the forward portion of the doors add to the other glazed areas of the sloping-front and slightly curved front screen door windows and large rear panels to give all-round visibility.
The display of instruments is neat and gave prominence to the most used instruments and allimportant functions are monitored, To make the entry suitable for urban delivery work, the cab is mounted low on the chassis and the floor pan has a low hump to clear the engine.
Rubber floor covering fitting. flush to the opening each side also insulates the cab against noise from below.
Both gear and park-brake levers are located between driver and dual passenger seat.
Ford claims that a major objective in the design of the new model was to improve access to all components, and radiator header tank, oil filter and dipstick are grouped together to the offside rear of the cab.
Two plastic twist-clips secure the front panel, which can be opened with a coin. There is a translucent clutch and a windscreen wash reservoir alongside a wiper motor, brake valve and the complete heater unit.
Inside the cab, a fusebox is located above the passenger footweli enclosed by a cover containing pictorial function indication.
Access to the engine for routine maintenance is achieved by tilting the cab to 40 degress. A further 10 degrees of tilt gives extra room for attention of a more serious kind.
Ford's own six-litre turbocharged diesel engine is located in the chassis at an angle of 45 degrees in order to keep the
overall height low and makes i possible to keep the internal cal floor height down to abou 0.98m (3ft 2.5in) above th, ground.
The chassis frame is smootl topped with the exception of twi bolt heads adjacent to the rea cross-member. Use of a high yield stress steel and careful de sign has produced weigh saving of about 33 per cen1 claims Ford.
For the first time Ford use spigot mounted wheels centre) on the wheel hub by fiy. hardened pins.
Our test vehicle cain. equipped with a long list of op tional equipment. These no only added £2,534 to the basi price but also 309kg (6811b) ti the unladen weight.
During the test the Cargo wa quick to accelerate to a cruisin) speed of about 60mph at 2,20 rpm in top gear. The most ece nomical running is indicated b. a green shaded area on the te chometer extending from 1,20 to 2,400rpm with a solid ban, from 1,600 to 2,000rpm.
At speeds above the legal km. for motorway running, mea sured on the test track, front-axl wheel imbalance created sever vibration. A reduction in spee, improved matters, but even a 60mph it was possible to detec a slight tremor. Overall brak performance was reassuring but the exhaust brake button.i placed awkwardly for operatior A large steering wheel 50cr (19.8in) and integral powe steering made light of twistin, lanes and slow speed ma neouvring. But when the Carg was driven quickly the fror single-leaf parabolic spring gave a degree of roll whic might have been reduced wit an anti-roll bar.
Heavy braking induced th soft suspension to dip drama tically.
The eight-speed all-synchrc mesh range-change gearbox i equipped with a well matche spread combining gradeabilit and performance and the silo) lever felt good and clea changes were easily made.
Revised servicing schedule are said to have improved conportent durability with item which previously required mair tenance designed out so thi less than 80 hours of routine se vice is needed over the course c 160,000km.
Clutch and brakes are self-ac justing, condensation in th tank drains automatically whil 3rake linings can be inspected thout removing the wheels d batteries need topping up ly once a year. Increased oil pacity and use of oil coolers s decreased the frequency of changes from 6,500km to ,000km.
JO MORE newcomers which ! put round the Welsh route !re the Scania P82M and dge Commando 2.
rhe Dodge, with a payload of nost 101/2 tons, set a fuel conmption record of 2 0.8 2 100km (13.57mpg) over the :Ish route for middleweights.
t just a marginal improvernt over the previous best, iieved by the Magirus Deutz our group test of last year, but er one mile per gallon or 8.8 r cent better.
'uel consumption improvernt with the new model is 16.4 r cent against the old model. rhe Mercedes 0M352 engine lich used to be an option on 1-016 chassis is no longer erecl. Nevertheless, the range engine options remains wide. rhe choice is between the 8bhp, naturally aspirated 354.4; the 148bhp, turboarged and charge-cooled .354.4; and the 172bhp, turally aspirated V8.540.
rhe most recent changes to r Perkins engines, are dened to improve fuel economy U durability, and reduce noise Karrier claims engine noise reductions of 2dB and 4dB at full power and torque respectively. The in-cab noise level we recorded at MIRA in the new Dodge made these figures quite believable. At a steady 50mph in top gear (6 high) the maximum noise level was 76dB(A).
At 60mph on the M4 section of our route, across-cab conversation was surprisingly easy, and up to the standard expected in premium tractive units but not generally in sixteen-tanners.
There is a new design of exhaust system on the Commando and noise insluation material is now fitted at the rear of the engine as well as at the sides.
No other sixteen-tonner we have tested is better suited to motorway work than this particular new Commando. With its six-speed overdrive gearbox and Eaton two-speed axle the Dodge's gearing meant that at 60mph the engine was revving at only 2,200rpm giving a quite remarkable motorway fuel consumption figure of 19.061it/100km (14.82mpg).
Compare, for example, this Dodge's 1 4.82mpg on the motorway with the 9.92mpg, over the same section, of the local delivery specification Scania, The Hestair Dennis Delta we tested in October last year, fitted with e same type of Perkins T6.354.4 engine achieved on our motorway section 27.2 lit/100km (10.39mpg).
Appearances of the new Commando have changed little. A taller grille made of ABS with large letters spelling "Dodge" is fitted. This is a "C" cab (standing for
comfort pack) which is standard on highway models.
All cabs still tilt only to 46 deg, with torsion-bar assistance. Access to the engine is not bad, the side noise insulation panels although now tilting with the cab, could be improved by allowing the cab to tilt to a greater angle.
Access to the driver's seat is improved by fitting a wider cast aluminium step and a larger grab handle to the "A" post.
The cab interior has been tidied up with a two-spoke steering wheel and new steering-column-mounted switches for wiper/wash and indicators.
A minor problem on our test vehicle was that when the clutch pedal was held down, gearbox noise was transmitted up into the cab and, indeed, amplified by the Bowdenflex. Karrier told us that this has been cured by inserting a damper into the cable.
Complementing the light clutch, Dodge's six-speed synchromesh gearbox was easy to use and the Eaton two-speed axle was much less temperamenta than many. One peculiarity 434 the gearing that needs to be re membered was that sixth geal (overdrive) with the axle in loyN was a lower overall ratio thar fifth (direct) with the axle in high
We felt that many operator; will agree with the principle ap, plied to the Commando facelit of leaving well alone and im. proving where necessary. If thE durability of the Perkins T6.354. has been improved by as much as its fuel economy, then surely no operators will have cause tc mourn the loss of the Mercedes engine option.
SECOND of the new sixteen ton! ners was Scania's P821VI, one o' the new GPR range of vehicler unveiled last year.
The vehicle tested was a 5.8rr wheelbase P82M 4x2 RN58 fittec with a 7.92m (26ft) Brade-Leigh alloy-framed platform body Model designation in the neln range reveals details about thE chassis specification.
Our M-rated chassis was thE lightest of the three available bui termed medium-duty by Scania. Cab access on the P82M waE .exceptionally good. Three wide non-slip steps are provided anc the doors open to 90°. There an deep and sturdy grab handles or each side.
Once seated behind the Sea nia's wheel, it is adjustable ove a range of 38mm (1.5in) fo height. Any one of four angles o rake, from 27° to 47°, may br chosen simply by pressing a re lease button on the steering co lumn. A thermostaticall, controlled heated suspensior
eat is fitted as standard and it as a multitude of adjustments.
The controls mounted above le engine hump are angled torards the driver including park Take lever, engine stop, hand irottle, gear-lever and trailer !rake lever (when fitted).
The angle is small and at first 'ere seemed no difference, but s the day's testing wore on we egan to appreciate that canting lese controls towards the drivr's seat does make the operaon easier.
On the throttle and gearhange rods, low friction nkages are resposnsible for re ucing driver effort to a finimum. Steering on our fully iden 16-tonner was a matter of nger-tip control at all speeds. If le wheel was gripped too ghtly, there was a tendency to ee-saw about the straight head position.
The heating and ventilation ystem in the Scania cab has
een comprehensively re-deigned and now has a glassfool filter, which, it is claimed, fine enough to filter out pollen .om air entering the cab.
Side-window misting should ot be a problem on the new canias as the demisterlrunking connected to ducts in the oors.
An electrically operated pasanger window window is standard on le P82.
No claims of improved fuel onsumption have been made
›r the naturally aspirated 7.8tre engine. In the P82M, the DN engine was driving through le same gearbox and rear-axle foe as was fitted to the LB81 M tested in October 1980 over le same route. So we expected le fuel consumption and avergo speed speed results to be similar nd they were.
On the motorway section from lernbury services to Aust ser ices at the Severn Bridge, the ew Scania used slightly less el than the earlier model, re 'ming a consumption of 28.48 11100km (9.92mpg) at an averge speed of 8 9.0 5 km/h i5.39mph).
The P82M's average fuel conJmption for the complete 210 )ile route at 26.85 lit/100km 10.52mpg) was marginally igher than the LB 81's, but the mall difference could easily ave been caused simply by trafc.
The kerb weight of the P82M Is ightly heavier than the LB 81, 'though generally, model for yodel, the new range is lighter }an the old.