TH1SWASATESTING TIME FOR VOLVO...
Page 24
If you've noticed an error in this article please click here to report it so we can fix it.
by Graham Montgomerie
METHODS of testing trucks from both the manufacturer's and the operator's point of view came under scrutiny in a Testing and Measuring Symposium organised by Volvo in Gothenburg last week.
Journalists from 11 countries took part in an exchange of ideas and viewpoints at the Haltered proving ground.
One of the major points stressed by all the journalists was that the operator is interested in how much money he can make with his truck. Everything else—be it ride, handling, braking or noise—is secondary to this.
Taking the noise problem to illustrate the point, the opinion was that this was a matter for the legislators and the manufacturers to sort out between them. Provided the eventual machine met all the required standards, this would satisfy the user.
The idea of a common test procedure throughout Europe was discussed, but the different gross weight limits in the various countries, for example, makes this virtually impossible.
While I was at the Hallered proving ground I took part in several tests including one to measure the effect of vehicle frontal area on fuel consumption. The truck used was an F88 rigid running at 16 tonnes gvw which was tested with and without a large vertical headboard.
The driver was instructed to maintain a constant speed of 80km/h (50mph) for two hours in each case. This average was maintained with great success as the truck covered 159.8km (99.3m) with the headboard and 159.7km without around the test track.
The fuel consumption with the increased wind resistance was 32.81it/100km (8.6mpg) compared with 25.31it /100km (11.2mpg) of the "normal" vehicle. This is an increase in the volume of fuel used of 24 per cent for an increase in frontal area of 23 per cent.
To demonstrate the difference in fuel consumption which can result merely by difference in technique, several drivers took a three-axle NSeries Volvo around the same 15.4km (9.6-mile) route. They were all aiming to cover the distance in around 20 minutes.
For the journalists, the fuel consumptions varied between 43.8 and 34.71it/100km (6.5 to 8.1mpg) which can be compared with the 34.01it/100km (8.3 mpg) achieved by the best Volvo works driver. This is the sort of variation which can occur with the same truck for the same average speed over the same distance.