The new software is called Volvo Torque Assist and is designed to support the driver to operate their vehicle more fuel-efficiently when not using cruise control.
“We have seen that there is a need to help drivers save fuel when cruise control cannot be used,” says Peter Hardin, Director Product Management at Volvo Trucks. “I-Cruise, our intelligent cruise control, is still the best way to optimize fuel consumption, but sometimes it might not be applicable. In this way we can support the driver to cut fuel costs in such driving situations.”
Volvo Torque Assist
Volvo Torque Assist improves fuel-efficiency by automatically adapting the truck’s torque and acceleration according to the road topography, load and speed. The system is designed to only deliver enough torque to maintain speed, and cuts any unnecessary torque. The function is activated when the driver presses the acceleration pedal more than needed. When driving downhill or on flat roads, the torque will be cut and acceleration reduced. The speed will still increase but at a lower rate. On uphill climbs, where full torque is required, Volvo Torque Assist will not reduce the acceleration.
Another supporting function within Volvo Torque Assist works by keeping the amount of injected fuel constant after the engine’s ‘green range’ has been passed, to avoid unnecessary acceleration. For the driver, this means that the torque, power and speed increase slower compared to the earlier version of the same engine. However, the lower performance is compensated for through improved fuel economy.
For example, if a driver attempts to climb a hill at maximum speed and at around 1800 rpm, Volvo Torque Assist will deliver around 14 per cent less torque (and save around 14 per cent in fuel). If the torque is insufficient, the engine speed will be reduced to a higher torque point using the same amount of fuel.
The pedal map has also been recalibrated, with a less sensitive pedal creating smoother torque development. This in turn makes it easier for the driver to control the truck and maintain the vehicle’s speed.
A more fuel-efficient driver
The result of these software changes is that any drivers should be able to achieve a high level of fuel-efficient driving regardless of their experience and expertise. “Drivers that are less skilled in economical driving benefit more than those who already have that driving style,” explains Peter Hardin. “The new software also gives a more significant result with heavy loads, many slope changes or large speed variations, while drivers transporting lighter loads with constant speed on flat roads will save less fuel. In field tests we have actually seen examples of a larger potential for savings, than the three per cent.”
In addition to the new software, many of the hardware upgrades that were introduced in the Euro 6 Step D versions of the D13 engine earlier in 2019 have now been extended to the Euro 3-5 engine versions. This includes a new cylinder liner with smoother surfaces and a new V-shaped oil scraper ring – both to help reduce internal friction. A new design for the turbocharger impeller improves turbo efficiency, while the engine management system has been upgraded to a newer version with better capacity. Combined the hardware upgrades save around one per cent fuel.