Pick up and go: the impact of transmission software

When are two identical gearboxes, fitted in two identical trucks, not actually the same at all? When those gearboxes are modern automated manual transmissions (AMTs), which means there’s a computer between the driver and the machine. Lucy Radley speaks to three OEMs about the electronic brains behind their boxes of cogs, to find out just how important the software really is.

Gearbox software is all about how quickly the transmission shifts gears, and when it shifts gears, according to Ashlea Awbery, sales engineering controller at MAN. This German manufacturer fits ZF’s TraXon hardware, and is by no means alone in making that choice. Once MAN’s software is installed to match the base transmission to the characteristics of its own engines, the end result is Tipmatic.

“If you’re driving with a manual gearbox and you want to go fast, you can accelerate, then hold it in gear for much longer than usual,” Awbery states. “Or, if you’re trying to save fuel, you can rev it very gently and shift very quickly between gears.” Having different software options enables drivers to do the same thing with an automated manual gearbox, the version installed having been chosen to match the application.

“For instance, if it was off-road software, it would hold on to the gears for much longer, so you didn’t lose traction,” she continues. “Whereas if it was software for an emergency services vehicle, where it would rev very quickly, it would change as quickly as possible to keep the speed going.”

MAN has two different software versions for fuel economy. The standard ‘Efficiency’ programme comes on all vehicles, keeps fuel consumption as low as possible, but does still allow manual override and kickdown for overtaking manoeuvres. Then there’s ‘Efficiency Plus’. “This doesn’t allow kickdown or manual gear changes, and is very much aimed at fleets,” Awbery says. “It stops drivers from interfering, though it does allow them to shift down to use engine braking.”


At the other end of the scale, MAN also offers a performance package. “This is for vehicles that regularly run at 40-plus tonnes in hilly areas, where operators might want it to make climbing a little easier – it’s popular in Scotland and Wales.” Then there’s heavy haulage software, refuse collection software designed for stop-start work, and tanker software. “That speeds up and slows down the vehicle very gently,” says the sales engineering controller, “to stop liquid loads from pushing the vehicle over the line at traffic lights, for example.”

The obvious question is why we have to choose between these when speccing the vehicle – couldn’t we just have them all? “There’s a limit to how many versions you could store on a vehicle,” Awbery replies. “Plus, realistically, how often will a driver want to chop and change?” It’s a fair point. “If they have the standard ‘Efficiency’ software and, say, the tanker software on top of it, it’d be very easy to toggle between the two.” If an operator does want to install a new package, they can, and they don’t even have to go to a dealership to do it – wireless data updates are now a reality for MAN.

The other area where software shows its mettle is when the driver needs to reverse or creep the vehicle forwards. While this can be done by finding clutch bite in the range of the right pedal, that isn’t recommended, so the latest versions of Tipmatic include specific manoeuvring modes. These give the driver maximum control at low speeds, although that isn’t actually their aim.

“When you manoeuvre with a manual gearbox, you slip the clutch to a certain extent, to feed the speed in,” Awbery explains. “Without the manoeuvring software, our clutch is designed to be fairly in or out, so between gear changes it’s like an on-off switch.” If drivers attempt to do the same as they would in a manual, the repeated ‘in-out’ effect would very quickly heat the clutch up, dramatically reducing its life.


DAF also uses the TraXon gearbox, choosing to keep that name for use in its own literature. “TraXon is a recognised name, so it’s a bit simplistic to try and mask that,” marketing manager Phil Moon says. “It’s a very popular gearbox produced by a premium supplier.” Behind the wheel, however, and controlled by software specifically developed for the DAF, this feels like a different transmission completely – just as using different browsers on different PCs results in a different experience using the internet.

“DAF has its own installation and application for the gearbox in the DAF truck range,” he continues. “Back in the days of non-vertically integrated manufacturing in the UK, if you wanted a part for your Fuller gearbox, it might have had the same part number whether you bought it from ERF, Foden or whoever.” Now there are DAF part numbers for all – even though some components will be shared with other TraXon users.

When it comes to differences, an easy example to pick is the ‘Urge To Move’ feature available on the new-generation DAF. Specified as an option in place of the standard manoeuvring mode, this utilises the same button on the gear selector stalk – albeit labelled UTM, rather than a tortoise symbol. “Pressing that button will make the vehicle behave like a full automatic, by slipping the clutch,” Moon tells us. “So if it’s in gear, to stay stationary, the driver must hold the footbrake on.”

To put it another way, the driver is using the brake pedal rather than the throttle pedal to moderate the clutch engagement. This means that, in stop-start situations, such as crawling traffic, there’s no need to move your foot between throttle and brake, the result being a far more comfortable drive. Urge To Move is not, however, suitable for use for very extended periods of time, as in situations such as domestic waste collection – because it works by slipping the clutch, overuse would trigger warnings to protect the clutch from overheating.

Like MAN, DAF offers specialist off-road, heavy haulage and liquid transport software options, but another place the two diverge is with their Eco modes. DAF has two variants, which to some extent overlap. ‘Eco Fuel’ is completely fuel-economy orientated, while ‘Eco Performance’ holds on to gears longer and is aimed at those operators working or based in more hilly areas. Both packages include an ‘Eco Off’ function via a button on the right-hand stalk, with Eco Performance being equal to the Eco Off setting of the Eco Fuel option.

“Eco mode is not just to do with the gearbox, it also affects the vehicle in terms of cruise control response,” Moon explains. In other words, the gearbox software isn’t a standalone ‘component’, rather it works in conjunction with software controlling other parts of the truck. It is this, as much as anything else, which leads to the dramatic differences in how the vehicles feel to the driver.

Continuing on that theme, there are subtleties between the set-up for different DAF engine ratings as well, particularly in the highest horsepower variant, the 530 (523bhp). “If you’re driving a 530 with Eco Performance and you switch Eco Off, it will give you maximum engine performance,” Moon tells us. “The principle being that if someone specs the 530, they want it to really pick its feet up and go, because they’re pulling high weights or over harsh terrain.”

This is an area where DAF’s philosophy has changed over the years. When it first introduced Eco mode in 2015, that feature was criticised for having too dampening an effect, the idea being that the driver should be reined in. “Over the years we’ve progressively relaxed our approach,” Moon admits. “So now Eco mode is not as compromising to performance as it would have been.” Nowadays, it’s all about giving the driver the tool and then training them to use it effectively.


One of the biggest steps forward when ZF moved on from AS Tronic, TraXon’s predecessor, was the introduction of a ring-shaped clutch actuator. This acts directly on the clutch, and made clutch control far more precise than in the past. It is also something which had already been a feature of Volvo’s I-Shift – widely accepted as the industry benchmark for AMTs – for some years. In fact, that actuator is just one example of how, in Volvo’s case, hardware has an equal part to play.

“In the main, we offer the direct-drive top gear I-Shift, which is the most popular, and we offer dual clutch, for really fast changes,” explains John Comer, Volvo head of product. “We can also put crawler gears on the front, which are ideal for heavy haulage and really arduous work.” That doesn’t mean heavy haulage trucks don’t have specialist software as well, just that the performance differences aren’t down to that alone. “It’s a mixture of both, so you can fine tune the gearbox to the application.”

When it comes to fuel efficiency, Volvo again offers both software and hardware solutions. Not only are there separate ‘Economy’ and ‘Performance’ modes, but operators can choose whether or not to fit a lever for manual gear changes on the seat arm. The vehicles destined for large fleets are usually specified with buttons on the dash for drive, neutral and reverse alone.

One thing Volvo has never seen a need for is a manoeuvring mode. “What we have got is four reverse gears, but we’ve always had that really good clutch control,” Comer points out. “So the vehicle has always been good on its own.”

Echoing others, he emphasises the importance of integration with other vehicle control systems. “The other key driver is connected software,” Comer adds. “So for all of our long-haul sales now, the gearbox software is linked to I-See, the predictive cruise control (PCC), which then connects to features like Eco Roll,” a fuel-efficient coasting mode.

Of course, even before PCC, the gearbox was linked to the engine brake. “That was then linked to brake blending,” Comer says, “so that when you went for the engine brake or retarder you were always in the right gear to get the maximum effect.” Then, of course, there’s clutch life. “Drivers had a habit of pulling off in second, but an I-Shift will work out what gear it needs, using sensors around the vehicle, working out the load.”

The key lesson learnt from discussing this subject is that it’s a mistake to look at any kind of software, gearbox-related or otherwise, on its own. The latest modern vehicles are all about the bigger picture, where the gearbox is just one of many, fully integrated parts – including the driver, who often gets forgotten in this brave new world.

Related content