It’s hard to make a heavy-duty cabover truck aerodynamic. Simply by design, they have the drag co-efficient of a dunny door.
It’s a lot easier to make a bonneted truck slippery through the air than it is to make a cabover streamlined.
However, the big European truck manufacturers have done their best over the years to get the most efficient aero shapes out of their trucks to eek out the last few percentage points of fuel savings through aerodynamics.
The latest of these is the Volvo Aero which will be able to be ordered as this story goes to press.
We were fortunate to be offered a drive of one of the first Volvo Aero cabs in the country for a run from Brisbane to Sydney.
Aerodynamic improvements have been achieved by extending the front of the existing FH cab by 240mm, allowing for a smoother more rounded frontal area to reduce drag and energy consumption whilst remaining within the 26-metre B-double limit.
The Aero will be available in Australia with a choice of 13-litre and 17-litre Euro 6 diesel engines well as Volvo’s heavy-duty electric driveline.
Our test truck was powered by the I-Save turbo-compound 13-litre engine which is rated at 500hp and puts out an impressive 2800Nm of torque.
Volvo tells us that this engine is ‘the ultimate fuel saver’ and in testing it proved to be up to 14 per cent more economical than the regular 13-litre engine.
The new Aero cab also adds to the fuel savings and in European testing, we’re told that the Aero cab got 5 per cent better economy than a regular cab.
So, what we’re looking at here, on paper at least, is a fuel saving of nearly 20 per cent.
The proven 540hp engine also remains an option for Aero as does the new D17 powerplant in ratings from 600hp and 3000Nm up to 700hp and 3400Nm. Aero cab options span sleeper, Globetrotter XL and Globetrotter XXL cabs.
To add to the aerodynamics and subsequent fuels savings, the Aero cab has no external mirrors. In their place is Volvo’s recently released Camera Monitor System which comes as standard equipment on the FH Aero.
CMS has digital cameras instead of mirrors. Two screens mounted on the A pillars in the cab provide a great view down the sides of the truck.
They feature a zoom-out function, automatic panning that tracks the rear of the vehicle while negotiating intersections, fixed reverse panning and an infra-red mode for low-light conditions.
Externally, all you can see are two stalks high on the cab which house the cameras. The camera lenses are heated and will automatically activate depending on the outside temperature to give a clear view in all weather conditions.
Our test truck was also fitted with Volvo’s Dynamic Steering which is an electrically assisted steering package that helps in low-speed manoeuvring as well as being more accurate on the highway at higher speed.
The Dynamic Steering also enables the Aero to have the new Pilot Assist feature which is Level 2 autonomous steering that ‘reads’ the line markings on the road and actually steers the truck for you.
It is actuated from the cruise control buttons on the steering wheel and not only gives the active steering but also radar cruise control, so it really does make the driver a steering wheel attendant.
I used this a bit on the highway and found it actually gives the driver a break when there isn’t too much traffic about.
Of course, being a Volvo, the FH Aero is fitted with all the other latest safety features. These include air bags, downhill cruise, hill hold, Collision Warning with Emergency Brake, Driver Alert Support, corner camera, lane departure warning, ESP, and more.
Inside, the FH is familiar territory. The expansive dash has everything close to the driver and the view is great – especially so in the area of peripheral vision as there are no mirrors to impede the view.
Our test vehicle was in a ‘fleet spec’ which included dash-mounted transmission buttons as opposed to the usual small T-bar shifter close to the driver’s seat.
This meant that the fridge was closer to the driver which isn’t a bad thing, but it also meant that if you wanted to manual-shift, you have to reach for the buttons rather than drop your hand down beside your thigh.
On the road
Getting comfortable in the big Volvo is easy with the steering wheel being multi adjustable, as is the driver’s seat.
The seat itself is a beauty with arm rests on either side and a heater for those chilly morning starts.
Fire up the 13-litre six and you’re greeted with a lovely burble and next to no vibration. Hit the button on the auto shifter and flick of the electric park brake, give a little tug test and we were off in the early morning on our way to Sydney from Volvo’s HQ in Wacol.
Wacol, incidentally, is where these trucks will be built starting next year.
Our truck was towing a B-double set of tautliner trailers weighing in at just a smidge under 60 tonnes which is a pretty honest load for a 13-litre.
However, the torque in this turbo-compound Volvo was impressive from the start with the truck skipping up the gears to the top of the box in no time. This particular version of Volvo’s I-Shift transmission is an overdrive box meaning that 12th gear is overdrive and 11th gear is direct 1:1.
The diff ratio is 3.09 and it all translates to a very low-revving engine. In fact, at 100km/h in top gear, the engine is spinning at just 1250rpm and on the hills it will lug down below 1000rpm before kicking down to a lower gear.
And it’s quiet. With no mirrors and no external visor – it has a very effective pull-down internal visor – there is next to no wind noise, and the insulation from the engine bay is fantastic.
There is no problem having a conversation with your passenger or listening to some music on the newly-upgraded stereo. In fact, as we were cruising down the coast we could hear the cicadas in the trees, it was that quiet.
The ease of driving is worth noting too. It seems that heavy-duty trucks are getting easier and easier to drive, and once I got used to the controls and the steering wheel buttons, I found I was basically driving with my thumbs.
Setting the cruise and the downhill speed on the steering wheel and using the engine brake stalk for slowing – it was a breeze.
Then, if you factor in the Pilot Assist which steers the truck, there really isn’t much to do. I admit to being initially sceptical about these semi-autonomous options on big trucks but I admit that if they’re used frugally, they can be a big asset.
The Pilot Assist doesn’t let the driver fully take their hands off the wheel, you have to apply some pressure or input or the system will flash up a message on the screen.
If you fail to acknowledge the message or put your hands back on the wheel, the system will assume that something has happened to the driver, and it will bring the truck to a stop and turn on the hazard lights. So, it is actually a safety feature.
It is difficult to say what benefits to economy the Aero cab actually has without doing a back-to-back comparison test with a regular FH cab, for that we’ll have to go with the European testing and accept their five per cent figure.
But we did keep a record of the fuel figures we achieved on our run from Brisbane to Sydney.
On the run, which totalled 944 kilometres, we achieved a best fuel figure of 2.2 km/litre (45.5 litres/100km) and an overall fuel figure for the run of 2.17 km/litre or 46.6 litres/100km which is very good considering we were at 60 tonnes.
It’s also worth noting that this truck was new. When I picked it up from Wacol, it had less than 2000 kilometres on the clock, so as the engine loosens up, the economy is sure to improve.
After my drive, what was really noticeable was how I felt after 12 hours in the saddle (minus the mandatory rest breaks, of course).
The smoothness and quietness of the truck really make it easier to do long runs, and after this run, I came out feeling great.
In the final wash-up, the combination of the Aero cab and the I-Save turbo-compound engine works on a number of levels.
Firstly economy. There is no doubt that this is an economical truck for doing medium-weight line-haul work.
Secondly, it’s a comfortable truck. Driver comfort is all-important these days and if the driver is comfortable, he or she is more likely to enjoy their job and stay in the truck.
Finally, safety. Volvo has always had safety at the forefront of its truck designs and this truck, with all its features and now with Pilot Assist and Front Short Range Assist for detecting vulnerable road users such as cyclists and pedestrians, has to be one of the safest trucks on the market today.
And that is surely what we’re all after.
Specs at a glance
Engine: D13K Euro 6 Step E
Max Power: 500hp (368kW)
Max Torque: 2800Nm at 900 to 1250rpm
Transmission: I-Shift 12-speed overdrive auto
Front Axle: 7.1 tonne
Rear Axle: RTS2370B single reduction tandem
Axle Ratio: 3.09:1
Wheelbase: 3100
Fuel: 970 litres
AdBlue: 150 litres
Max GCM: 70 tonnes
Safety: Volvo Safety Platform incl adaptive/downhill cruise, air bags, ABS/EBS disc brakes, auto hold, collision warning with emergency brakes, driver alert support, camera monitoring system, corner camera, rear camera, lane keeping, ESP