An air of calm

Truck Test 2017 featured one specific prototype vehicle that had everyone intrigued – the bewinged and bespoilered Aero Truck EPS MAN TGS 26.440. I asked Cameron and William Dudley-Owen of Aero Truck what all the fuss is about

I experienced something rather remarkable during Truck Test 2017. Pulling up and holding position behind the Aero Truck EPS MAN TGS 26.440, I flicked down the passenger-side window switch of our Mitsubishi Triton support vehicle and stuck my head and camera out the window for a couple of rear-facing tracking shots.

With both vehicles on a flat section of road and the MAN cruising along at (I presume) its 80 km/h maximum speed, experience told me to expect an assault of wind; as the air behind the vehicle would fight its way past me, around and into our vehicle through the open window – leaving me with one, literally, wind-swept hairdo in the process…

Experience, in this case, was incorrect. The air was, in all honesty, as calm as it would’ve been had the two vehicles been travelling at half the speed. All the while, wind buffeting in our vehicle was, according to the driver, just as calm. Importantly, too, what little hair I’ve not yet lost was still rooted to my scalp…

How was this so? According to Aero Truck, it’s all down to the Aero Tails fitted to the rear of the trailer. Increasing the length of the trailer sides by 750 mm, the Aero Tails are currently being tested with this rig using Abnormal Permits.

“The Aero Tails streamline the flow of the air at the rear of the trailer, which reduces drag and consequently fuel consumption. Tests in America, the United Kingdom and Europe have shown significant improvements in fuel saving with these units fitted,” the Dudley-Owens explain.

The tails work in conjunction with other aerodynamic addenda fitted to the rig, such as side “Filla” panels between the trailer units, chassis deflectors and under-chassis wind-deflection skins (which all smooth the airflow around and under the trailer, reducing turbulence), as well as a rear under-bumper deflector on the trailer (which deflects wind up into the vacuum at the rear of the trailer).

“This experimental test rig is on par with current developments worldwide. We have to bear in mind that this is an experimental vehicle, and we are using Truck Test 2017 to showcase the innovations. We hope to show a marginal improvement against vehicles which only have ‘off the shelf’ aerodynamic kits fitted, when pulling a comparable trailer,” say the Dudley-Owens.

They are cautious with their enthusiasm, though.

“The test route is, however, not ideal for demonstrating the improved aerodynamic possibilities of this rig: it is very short and the climb up Van Reenen’s Pass will push up average fuel consumption. The aerodynamics will be of no use on this section of the route, since it only becomes truly effective at higher speeds and over longer distances.”

That explains the wind-free photoshoot… If nothing else, this unique entry should spark some debate. So how did it perform? Turn to page 14 to find out.