Gravity’s Rainbow

A key element in Volvo’s Euro 6 line up is a 13-litre engine which utilises turbo compounding technology.

Volvo’s plan for the global launch of its comprehensively enhanced Euro 6 models was an early victim of the restrictions brought about by COVID.

While the subsequent ‘virtual’ launch delivered an abundance of information, more than a year later the trucks are finally available to drive on Australian roads and their numerous features can be better appreciated.

As expected of Volvo, this is more than a range of trucks focused on meeting the latest emission standards and the new models have plenty for everyone with cabs loaded with features to enhance the drivers’ working lives, advanced safety systems to improve protection of all road users, and even more fuel efficient drivelines plus a plethora of electronic wizardry which ties everything together.

Our test drive takes place on a wet Sunday along the Hume Highway between Sydney and the border city of Albury and a number of drivers cross over between four very different examples of the latest Volvo range.

A 700hp FH16, a 540hp FH featuring the dual clutch version of the Volvo I-Shift transmission, a 540hp FM and a 500hp FH fitted with the 13-litre I-Save turbo compound engine which seriously captures our interest as this form of technology appears to be making a comeback after going out of favour some years ago.

The 13-litre Volvo D13TC engine utilises turbo compounding technology which recovers energy typically wasted through the exhaust, converting the heat energy into useable mechanical energy which is transferred back to the engine’s crankshaft by way of a viscous coupling and a gear train.

Volvo says up to 50 ‘free’ horsepower are available resulting in up to a 6.5 per cent improvement in fuel efficiency from the engine when compared with the previous Volvo 13-litre engine.

The harnessing of the additional power and torque comes at no extra running cost and translates to a 500hp engine with the fuel demand of a 450hp engine.

The Volvo turbo compound technology is at its most basic description a waste heat recovery system which uses an additional turbine to convert energy from the exhaust gases into additional torque at the crankshaft and therefore improving engine efficiency.

The engine features patented wave top pistons with uniquely designed ridged piston crowns to burn fuel more efficiently by moving the air/fuel charge to the centre of the combustion chamber prior to ignition. The compression ratio has also been increased from 17:1 to 18:1, further improving fuel efficiency within the engine.

Externally, the fixed geometry turbocharger is fitted with ball bearings for an extended service life.

The maximum power of 500hp from the D13TC is available between 1,250rpm and 1,600rpm, with the maximum torque of 2,800Nm delivered from as low at 900rpm up to 1,300rpm.

The additional 300Nm of maximum torque being available at such low revs results in reduced application of the accelerator, either by the driver or the cruise control, so that steady speeds can be maintained on the highway.

The additional torque at lower revs also contributes to a better point-to-point average speed due to improved abilities by extending the time spent in higher gears when climbing hills or negotiating long stretches of gradient.

The maximum retardation of the engine brake is an effective 380kW @2,300rpm.

The Volvo I-Shift transmission has a new controller which makes it easier for the driver to toggle between the new drive modes which have been developed to extract the full advantages of the characteristics of the turbo compound engine.

Three main modes are now available: ‘Economy’ with an obvious focus on fuel consumption with some reduction in power, ‘Standard’ which maintains ‘reasonable’ fuel consumption without compromising driveability, and ‘Performance’ which delivers full power with a reduced focus on fuel consumption.

There are two other transmission modes to select from: ‘Off Road’ in which agility is prioritised, and ‘Heavy Duty’ which optimises driveability at high loads above 85 tonnes GVM.

Integral to the I-Save suite is the I-See system which uses GPS coordinates and shared topography data through a central data storage in the Cloud to maximise the vehicle’s efficiency by maintaining momentum and avoiding unnecessary gear changes.

The I-See system knows when a hill is ahead, so the truck accelerates and is able to remain in a higher gear for longer during the climb. It also is aware when it is approaching the crest so stops accelerating unnecessarily.

On the downhill side, I-See is able to disengage the powertrain to allow the truck to be pulled along by gravity and will apply the engine and service brakes as required to keep within the speed parameters set by the driver.

In the situation of a fleet of trucks being connected to the I-See system, it is enough that just one connected vehicle has driven a particular route, for all connected vehicles to be able to utilise the information and optimise their driving when they then traverse the same route.

When the vehicle operates outside GSM network coverage the I-See functionality will still operate using topography data from previous trips stored within the truck.

The FH is also equipped with Downhill Cruise Control (DCC) with Auto Service Brakes.

DCC prevents the truck from exceeding the speed set by the driver and primarily uses auxiliary brakes such as the engine brake to control downhill speed and only autonomously applies the wheel brakes when absolutely required. When the DCC is activated a symbol and the set speed are displayed in instrument screen.

If, and when, service brakes are applied another icon appears to indicate their use.

The DCC will enter a ‘Reduced’ mode to protect the service brakes from overheating and in this situation a message is displayed on the dash of ‘DCC functionality reduced’ and the driver may have to intervene to maintain speed at or below the predetermined level.

Normal DCC function returns once brakes have sufficiently cooled. Unlike traditional cruise control, the driver can operate the foot brake without deactivating the DCC cruise system and having to reset it.

The Adaptive Cruise Control now functions down to 0km/h, dropping from 15km/h in previous versions meaning the truck can come to a complete stop if it detects a stationary object in its path.

Another innovative safety feature is the Volvo Passenger Corner Camera located on the bottom of the kerbside mirror, which activates when the turn indicator is flicked to the left.

The camera’s view can also be activated manually using the camera button located below side display screen, which is handy when reversing or making a tight left-hand turn at an intersection.

A clear view of the side of the area along the kerb side of the vehicle is displayed on side screen in the cab.

The new cab’s LED headlights follow an iconic V-shape and incorporate four reflectors and 12 LEDs on each side.

The headlights have adaptive high beam which utilises the radar and camera components of the Adaptive Cruise Control to detect surrounding traffic and light sources.

If objects are detected, various LEDs within the headlight assemblies are switched off or on automatically to suit the circumstances. The Volvo Dynamic Steering as fitted to this FH has also been the subject of some changes.

The basic torque overlay of up to 25Nm results in a reduced steering force of up to 85 per cent which contributes to a lowering of driver fatigue. The default production setting is designed to give a balanced feel and should be ideal for most drivers.

However, personal settings are now easy to access through the side display screen in the Vehicle Settings menu.

There are a number of pre-defined settings including ‘Light’ which provides very light steering but is still damped, ‘Stable’ which is good on narrow roads, ‘Responsive’ which delivers a car like feel due to its high spring, low damping and friction settings.

In ‘Custom’ mode the driver is able to set and save their own steering preferences. The power steering pump is now of a variable displacement design to provide its own contribution to fuel economy.

In revisiting the turbo compound engine technology which it and others had walked away from in previous years, Volvo has succeeded in harnessing the significant fuel efficiencies this type of engine offers and surrounded it with a comprehensive suite of technologies to produce a truck with a high level of innovations accentuating safety, driveability and efficiency.