Master of the hills
Anyone who has ridden a bike downhill and switched to a harder gear to increase speed to make it up the next hill will appreciate Scania Ecocruise, the eco-driving cruise control launched in 2006.
TEXT: ALEXANDER FARNSWORTH
Scania Ecocruise is basically a system for fuel-efficient driving in hilly terrain. Ecocruise mirrors the driving behaviour of an experienced driver trained in driving economically.
A cruise control for eco-drivingBut unlike regular cruise control, which retains a chosen speed regardless of the terrain, Scania Ecocruise avoids accelerating over the crest of a hill (unless the truck’s speed has dropped by more than 20 km/h) and instead maintains a higher speed to keep the momentum at the bottom of the hill, when the truck has accumulated kinetic energy down the hill.
“Scania Ecocruise determines that the crest of the hill is soon approaching so it lifts off the gas,” says Magnus Staaf, Head of Control Strategy, NEC Powertrain Control System Development at Scania.
Improving fuel economy“On the way down it uses the momentum and maintains the set downhill speed for a while at the bottom to make use of the free kinetic energy,” he continues.
According to Scania’s own calculations, Ecocruise can save around 4 to 5 percent in fuel costs for a truck negotiating hilly terrain, compared with a normal cruise control. In addition, the spread between different drivers in terms of fuel economy narrows significantly with Ecocruise.
“The cost in time – maybe 15 minutes in a working day – is often found to be negligible for drivers and hauliers compared to the savings,” says Staaf.
Naturally, driver intervention is possible at any time either with the accelerator or by changing gears.
Scania Ecocruise is intended for use with Scania Retarder (braking) and Scania Opticruise (automated gearchanging) systems, and it is offered as an option across the whole Scania truck range.
How Scania Ecocruise works
Scania Ecocruise is programmed to avoid acceleration at the crest of a hill, when acceleration consumes a lot of fuel and the gain in time is negligible.
At the end of the hill, the system strives to use the truck’s kinetic energy and maintain speed by applying the throttle for a short time, thereby raising the entry speed for the next hill and ultimately improving the overall fuel economy.