Two Mercedes-Benz Actros 6x4
truck-tractors, fitted with the latest Mercedes-Benz RT440 hypoid
axles as standard, have achieved significant fuel savings of more than 5% in
test runs in the Eastern Cape.
Fuel economy in vehicles can be improved
in many ways, including increasing engine efficiency, reducing aerodynamic
drag, rolling friction and improving the fuel quality among other things.
Mercedes-Benz engineers have developed a
new hypoid rear axle for the current Actros 2644LS/33 and Actros 2654LS/33 6x4
truck-tractors that were tested under everyday conditions along Mercedes-Benz
South Africa’s (MBSA) well-known trial routes in the Eastern Cape.
Mercedes-Benz trucks combined the OM
502LA engine with its 540 hp with the RT440 hypoid rear axle in the Actros
2654LS/33 which replaces the other air-suspended 2650LS/33. It now has a 3.583
rear axle ratio.
Christo Kleynhans Mercedes-Benz trucks
product manager says: “The new RT440 hypoid rear axles make for the most fuel
efficient Mercedes-Benz 6x4 truck tractors of all times In fact, the fuel
saving achieved on the 2644LS/33 was 5.67% and on the 2654LS/33 was 5.37%.”
It is an on-going quest in which Mercedes-Benz
trucks; the first manufacturer to complete the launch of a full range of Euro
VI-compliant trucks in Europe continues to reduce fuel consumption and
emissions in South Africa.
However, technological advances by the
Mercedes-Benz SA holding company, Daimler AG, in Europe cannot always be
implemented locally – a prime example being South Africa’s inadequate
availability of cleaner fuel which prohibits the introduction of “greener” and
more fuel efficient commercial vehicles.
Kobus van Zyl, vice-president of MBSA commercial
vehicles expresses this frustration: “In the absence of the cleaner fuel that
is required by our advanced commercial vehicle models already available
elsewhere in the world, we can only try to
improve the performance and total cost of ownership of the current range of
Clinton Savage, divisional manager for
Mercedes-Benz trucks says: “Light, economical and reliable – the range of
hypoid rear axles on these trucks offer not just reliable power transmission,
but also allows the most economical driveline for any operation.”
Kleynhans points out that South Africa is
well-known for its unique operating conditions and the trucking environment
which is spread across fleets ranging from first to third world and makes for a
testing ground suitable for a wide spectrum of applications. “Due to the
outstanding track record of the Mercedes-Benz Testing Department, it was an obvious
choice to call on their expertise to perform the comparative test between the
new hypoid axles and the existing hub reduction rear axles,” elaborates
During the fuel consumption testing in
the Eastern Cape region, the vehicles not only achieved the targeted fuel
saving in comparison with the predecessor models but already surpassed all
expectations early into the trial by proving to be even more frugal than
According to Kleynhans, the drivers at
the wheel of the trucks, with standard interlink trailers and gross combination
weights of 49 000kg (Actros 2644LS/33) and 56 000kg (2654LS/33) respectively,
were not Mercedes-Benz driver trainers, but normal fleet drivers.
Savage interpolates: “The consumption
figures of the two new Actros truck tractors are even more impressive in view
of the guidelines for the test. Unlike normal fuel consumption tests, the
comparative run were not carried out on a test circuit but under everyday
conditions on busy roads and at times, under adverse weather conditions.”
Kleynhans says that each vehicle
completed 9920 kilometers under some of the most extreme conditions on the
Eastern Cape roads. The test route of 620 kilometers started in East London and
then followed the N2 over the Kei River back onto the N6 and over Penhoek Pass
(1884 meters above sea level and maximum gradient of 10%) before returning to
East London. The accumulated climbing height for the total route of 620km is an
impressive 9389 meters.
During the comparative drive the test
engineers monitored every fuelling of diesel as well as the swapping of the
drivers and semitrailers. The aim of the latter was to rule out differences in
driving styles and the rolling resistance of the semitrailers which might
distort the fuel consumption measurements.
“As in normal long distance operations,
the drivers were allowed to travel at a max speed of 80 km/h and overrun to
87km/h on the down hills. All four vehicles were closely monitored on
FleetBoard to ensure the drivers followed the testing guidelines at all times. Physical
fuel measurements and kilometres readings were also verified against the
FleetBoard results,” van Zyl concludes.
For more information visit: www.mercedes-benz.co.za/hypoid