Mercedes-Benz Actros 2660 LS 6x4 prime mover

The Mercedes-Benz Actros 2660 LS 6x4 Prime Mover comes from a manufacturer that wants to be seen as the ‘safe’ truck manufacturer. Gary Worrall puts an Actros prime mover through its paces.

While there’s plenty of debate over who or what is actually to blame for the number of accidents involving heavy vehicles each year, truck manufacturer Mercedes-Benz is keen to improve driver safety with a suite of safety technologies in its commercial vehicle range.

Having had the opportunity to test a number of these technologies in the past on a closed circuit, I was a guaranteed starter when the invitation arrived for a day at the Mt Cotton Driver Training Centre in South East Queensland.

The Mt Cotton layout gives the chance to try a number of different vehicles in quick succession in a variety of scenarios.

The opportunity to then hit the road in the latest version of the Actros prime mover, complete with 600hp V8, pulling a 60-tonne B-Double combination made this a unique chance to gauge the direction of the Mercedes-Benz truck division.

Safety Features

For many, the concept of a motor vehicle that is able to ‘see’ obstacles on the road ahead and stop before contact is made remains in the realm of science fiction.

This concept is now a reality, with a number of European manufacturers offering a form of adaptive cruise control not only in cars, but for trucks as well, with Mercedes-Benz leading the way, courtesy of shared research with its passenger car division.

Add to that other safety advances like Telligent lane assist and proximity control, Active Brake Assist 2 and a gearbox retarder, all linked through the engine management system that also oversees the Powershift automated manual transmission, and it makes for a very intelligent truck. Even better, hook up trailers fitted with EBS (Electronic Braking System) and the result is a total combination that can identify and react to road hazards faster and more accurately than any human driver.

Much as a claim such as this could be seen as simply a regurgitation of a corporate press release, it’s based on solid fact, as the staff from the Mercedes-Benz Driving Academy set out to prove during our visit to the Mt Cotton centre.

Rather than providing a blow-by-blow account of every activity on the day, suffice it to say that the tests and demonstrations show just how effectively the on-board systems work.

As an example, to demonstrate the Telligent stability control, which is Benz-speak for ‘electronic stability program’, Owner//Driver was invited to drive an Actros prime mover towing a trailer fitted with outrigger ‘trainer wheels’ to prevent the truck from tipping, at ever-increasing speeds in a tightening circle.

As any truck driver, or indeed student of physics, will point out, this is an invitation for the inside wheels to begin lifting and, in normal circumstances, the whole combination to drop onto its side and slide to a stop across the bitumen.

In this case, the trainer wheels did their thing and caught the trailer before any real harm was done, to either the equipment or the driver’s ego.

Our instructor, with a mix of nerves of steel and complete faith in the product, switched the stability control system on and asked us to repeat the experience.

As predicted, the sensors fitted to the truck and trailer detected the mix of speed and steering angle, as well as the trailer beginning to lift the inside wheels, activating the stability control program.

Using a combination of individual wheel brakes and cutting power, the Telligent stability control ensured the truck never reached a point where it was in danger of falling over.

Regardless of the driver applying more throttle, the engine revs were even cut at one point, to ensure the truck never exceeded the ‘safe’ speed to complete the manoeuvre.

A similar result was achieved in the demonstration of Active Brake Assist 2, the latest weapon in the Mercedes-Benz crash-avoidance armoury, an extension of the sensational Telligent proximity control autonomous cruise control system.

Where Telligent proximity control and its predecessors broke new ground in being able to control the speed of a fully-laden

B-double by using radar to detect slower moving vehicles in its path and then maintain a pre-set gap, the latest iteration takes that to a stunning new level.

Demonstrated to the press with an E-Class sedan fitted with the similar Distronic Plus system, participants were instructed to speed up to 80km/h, then drive at a triangle target, mounted on a spring-loaded mechanism so that it drops flat on impact.

Now, it’s not often vehicle manufacturers tell you to run something over deliberately — they tend to get a bit cranky when it happens even by accident — so this was too good an opportunity to pass up.

What they didn’t tell us was that the car had been ‘idiot-proofed’ so that even if a stationary object is approached at speed, the safety systems won’t allow the driver to get away with it.

Instead, there was a warning beep when the car was about 2.5 seconds from impact, just in case the driver could not see the obstacle, followed by a double beep and 40 per cent application of the brakes; then finally a full-on emergency brake when it became apparent there was no chance of the driver missing the target.

Most impressive, this will happen even if the driver is foot-to-the-floor on the accelerator. It is an ‘always on’ system, designed to offer maximum protection for the driver and passengers in the vehicle.

But wait, there’s more, as the TV ad used to say. When the Telligent proximity control is in use, the radar will automatically detect the obstacle and immediately begin avoidance measures to a maximum of 50 percent braking effort, significantly reducing the possibility of a nose to tail collision.

Benz stress the ‘virtually’ on the basis that there are situations that even the radar and computer cannot deal with. However, the point of the system is that it allows the driver to spend more time looking outside of the vehicle checking for potential threats, so that between the human and the robotic, there is almost no chance of accidents occurring.

Other demonstrations included a refresher on using the lane assist, where a digital camera mounted on the windscreen ‘reads’ the line markings, and if the truck crosses over a line after the road speed passes 60km/h, then the driver is rewarded with a rumble strip sound through the stereo system on the side of the infringement, warning them that the truck is leaving its lane.

Also included was a stint on the skid pan with a Vito van and an E500 luxury sedan, and being invited to drive at speed through a slippery mix of diesel and water, with predictable results of the vehicles gyrating crazily across the concrete, amid peals of laughter from the driver (err, me!)

The instructors then activated the stability systems and asked us to repeat the exercise, at which point the vehicles would start to snap sideways before the computers would cut power and apply brakes as needed to bring the car back under control.

The grand-daddy of them all, of course, remains the proximity control demonstration, where high ranking Mercedes-Benz staff are loaded into the back of a sedan, which then weaves in and out of the path of a fully-laden semi-trailer travelling 20km/h faster.

As the car cuts the truck off, the radar automatically slows the truck to the car’s pace, and then maintains the gap until the car speeds up or moves out of the way, when it resumes the preset speed.

After a 350km test of an Actros B-double and a week-and-a-half punting a new C-Class sedan around Brisbane, I have to say that it was me who backed down before the computer ever went wrong!

Engine

The 16-litre V8 is well sorted, having served many years in the Actros in Euro 4 and Euro 5 guises, and it’s well and truly up to the task of propelling a fully-laden B-Double along the highways of Australia.

Transmission

Keeping pace with the engine is the PowerShift transmission, with the shifter in ‘auto’ mode allowing the computers to make the call, there was never a problem with fast accurate shifts; the computer would simply cut the throttle for a tiny fraction of a second while the gear selector moved into the next appropriate cog.

Performance

While the closed road tests are a lot of fun, the one thing they cannot portray is the feeling of driving the Mercedes-Benz Actros prime mover over a couple of hundred kilometres of bad roads, in real traffic, with lane closures, speed limits and best of all, cars (not the movie, the traffic).

So, after all the fun was had and the toys returned to their rightful custodians, the chance came to hit the highway, driving from Brisbane up the Toowoomba range, along the Great Dividing Range towards Warwick, down the hill at Cunningham’s Gap and then back to Benz-land in Brisbane.

Over smooth roads, the Actros is without doubt one of the better rides available to transport operators. However, less than six months after the worst flooding to ever hit South East Queensland, and despite all efforts to fill in the holes, the road network in many places can still only be described as sub-standard.

This is possibly the biggest downside to the Actros: with suspensions set stiffer for smoother road surfaces, it begins to feel unsettled by the poor road conditions, even at speeds under the 100km/h maximum.

What makes this doubly disappointing is the sensational performance of the Telligent proximity control, having dialled up the posted limit of 90km/h on the outbound leg it then studiously maintained the gap to the vehicle ahead of me, which can be adjusted courtesy of a twist knob on the right-hand column stalk, backed up by a visual on the colour display screen.

When the limit dropped to 80km/h through the never-ending roadworks around Goodna, the cruise control could be adjusted down to suit, with the radar cheerfully keeping the gap constant regardless of road speed.

After clearing the city limits and taking the Warrego Highway exit, it was time to wind up the speed, opting for a self-imposed limit of 95km/h that allowed the hot-shoes to slip by without adding more than a couple of minutes to the overall timesheet.

At this point, the true benefit of the combined computer control of the Actros revealed itself. With no need to monitor the ‘minor’ operations of the truck, it was possible to relax a little and become more aware of the bigger picture unfolding around me, including speed limit changes as sections of road still in a poor state of repair were either signposted as ‘dangerous’ or where roadworks were actually underway to fix the potholed surface.

It also allowed for plenty of time to keep an eye on the mirrors, ensuring the trailers track down the road properly while ensuring there were no ignorant cars failing to spot the twin trailers and attempting to merge with the B-Trailer.

In the case of our road test, the engine was truly capable of pulling a fully-laden B-double, including not only the rollercoaster ride of the Warrego Highway west to Ipswich, but also the taxing climb up the Toowoomba Range into the Garden City.

On the flatter sections heading west, the Actros had no problems with multiple speed changes, even just responding to the driver’s foot, the V8 note varied between the muted rumble of constant speed cruising to the more aggressive sound of distant thunder as the throttle opened to pour on some power for overtaking or speed changes.

Beginning the climb up the hill, I decided to let the computer have a go, and dialled in the required speed on the cruise and let the system sort itself out.

This proved to be a revelation, while there is no ‘eye’ to tell the truck what the road is doing, the combination of sensors soon figured out what was going on and pulled the transmission back to put the power down and keep up momentum.

Again, this frees the driver from the daily concern of worrying about matching engine revs to the road speed to staying on top of the road conditions, and not arriving at the next corner too fast, or crossing the centre line on tight corners.

Having climbed the mountain many times in a variety of vehicles, the Actros is one of the easiest I’ve ever made the trip in.

In no time at all, the Actros was cresting the top of the mountain and entering the Toowoomba traffic zone where 60km/h is the go, a quick flick of the cruise control guaranteed a sensible maximum, although, to be honest, there were so many sets of traffic lights to negotiate that cruise control was sent to the back of the class awaiting more open road conditions.

What did cop a workout, of course, was the multi-stage Voith Retarder, operating on the transmission rather than as an engine brake, in heavy traffic it can be left in the fourth and fifth positions for massive and instant intervention.

While this may seem a little drastic, it was better to have more braking force than necessary, which could be backed off, rather than be left wanting in an emergency.

A quick jaunt down the New England Highway confirmed the earlier suspicions about the prime mover suspension being set too stiff for poor-quality roads.

This is a shame, as what is otherwise a technical tour de force suffers at the hands of flood-ravaged road surfaces.

This is an important distinction to make: individual potholes were not the problem, they were dispatched with a minimum of fuss and perhaps a slight jolt through the driver’s feet.

Instead, the real culprit was the section of road that collapsed when its foundations were washed away, leaving multiple dips and hollows that felt as though the suspension was at full stretch, before suddenly the road reappeared and forced the prime mover to jump around.

With the ability to spend so much time focusing on what is ranging up on the truck, combined with the light speed reactions of the Telligent proximity control, there were no emergency brake situations to test out the EBS brakes of the Actros.

Instead, there were ample demonstrations of the systems combining to make the drive simple, with the computer intervening well ahead of the human as it sensed and reacted to potential threats.

Similarly, the big drive back down to sea level via the equally flood-affected Cunningham’s Gap favoured by Brisbane-bound trucks travelling north from Melbourne was a chance to put the retarder to the test.

By locking the transmission in sixth gear and applying full retardation, the Actros was a breeze, serenely cruising down the steep inclines at a stately 40km/h, while the temperature gauge remained safely within the operating range.

After reaching to the bottom of the range, it was simply a case of resuming cruising speed and setting course back for Brisbane, thoroughly impressed with the performance of the Actros.

While this doesn’t replicate thousands of kilometres running up and down the highway, having pulled two loaded trailers along the highway, and then up and down two of the most taxing mountain ranges in the country, it’s safe to say the Actros is worth putting on the shopping list for a proper evaluation.

Quite simply, it is comfortable and easy to drive, while the available range of safety systems should be enough to get the truck onto everyone’s shopping list immediately, so efficient are they at protecting life and property.

Verdict

While it might be a slogan for government agencies, in truth it is manufacturers like Mercedes-Benz that are out to make them a reality, developing a range of safety aids for drivers that will help keep them out of trouble, or minimise the damage if things go really wrong.

It took manufacturers to begin installing seatbelts in vehicles before government made them mandatory. It was manufacturers that developed the front under-run protection systems that will become mandatory in 2012.

While this inequity continues, with legislators unwilling or unable to talk to manufacturers and operators about what technologies are possible, and when, operators will struggle to see the worth of additional safety systems that cannot be used to increase revenue for the business.

In reality, it’s the in-built safety systems that contribute to reduced accident rates for those operators that make the investment, with the payback coming in the form of better insurance premiums and fewer payouts as a result of accidents and injuries.