OPEN RANGE HAVING TESTED A NUMBER OF V8-POWERED SCANIAS OUT FRONT OF HEAVY-WEIGHT B-DOUBLES OVER THE YEARS, PRIME MOVER WAS KEEN TO SAMPLE THE SIX-CYLINDER SCANIA NEW TRUCK GENERATION R 500 TO DISCERN WHETHER OR NOT IT HAS THE GOODS TO DELIVER IN THIS DEMANDING APPLICATION.
T
he mission Prime Mover chose to accept was to determine whether the renowned fuel efficiency of Scania’s sixpack powertrain can be harnessed with acceptable performance hauling a B-double with a gross combination mass (GCM) north of 60 tonnes on an undulating route east of Melbourne. Considering most current multi-trailer prime movers sport 550 or 600hp ratings, ‘Is 500hp enough?’ seems a fair question to ask. Perhaps more to the point, ‘Is there a place in the Australian full-weight B-double (or dare we also mention A-double) market segment for 500hp prime movers? Of course, many variable factors must be taken into account, including average GCM and the extent of undulations on the route most travelled. It’s surprising, for example, how much difference a 55 tonne GCM compared with a 62.5 tonne GCM makes to the average speed of a combination on a long and steep climb. Interestingly though, making a decision on the horsepower rating alone could prove erroneous due to the fact that the torque rating often plays a more important role than outright horsepower in determining
the suitability of a truck for a given role. To put things in perspective, a popular engine rating for linehaul B-doubles is 550hp and 1,850lbft (2,508Nm) of torque. In comparison, Scania’s G and R 500 variants deliver 500hp and 1,881lbft (2,550Nm) of torque. So, while at first glance the 550hp rating might sound more impressive, it is the torque produced in the lower reaches of the RPM band that actually hauls the truck up the hill more so than the horsepower. Therefore, all things being equal, with its extra 31lbft (42Nm) of torque delivered between the exceptionally low 1,000 and 1,350rpm, the 500hp Scanias could potentially outclass 550hp opponents on a climb. But as the old adage regarding human behaviour notes, perception is often interpreted as reality meaning many will continue to believe that higher horsepower equals better performance. It can be a similar story in the sensory realm whereby a vehicle that makes more noise can be easily perceived to have better performance than a quieter one. This is a factor that has traditionally worked against European trucks in the Australian market, particularly when compared
with those originating from another part of the northern hemisphere where twin seven-inch chrome stacks were at one stage the signature feature of all-powerful prime movers. But time inevitably moves on and nowadays the quest to extract every ounce of bang from each precious litre of fuel, not to mention considerably lower emissions, has more or less overtaken the glitz and glam factor in terms of being the number one priority of most successful commercial haulage operations. With this in mind, Prime Mover settled into the premium black velour upholstered driver’s chair of an R 500 hitched to a curtain-side B-double set that according to a certified weighbridge docket was grossing precisely 60.7 tonnes. The docket also revealed ideal weight distribution with 6.4 tonnes on the steer, 16.3 tonnes on the drive and respective tri figures of 18.84 and 19.16 tonnes. This shows that the R 500 with its 3,825mm wheelbase is ideally suited to multicombination applications. Having started out from Scania’s Laverton branch, ahead lay a 379km round trip taking in the picturesque hills and dales p r i m em over m a g . c o m . a u
55
