Let’s Get DynActiv

Let’s Get DynActiv

Allison Transmissions explains how fleets running its transmissions can retrofit the latest technology, FuelSense 2.0 with DynActiv Shifting, and benefit from improved fuel economy.


Fleets running Allison transmissions are now able to benefit from an upgraded package that delivers diesel fuel savings of up to 6%, worth more than £1,000 per truck per year for many commercial vehicle operators. Any Dennis Eagle Elite or Mercedes Benz Econic built before May 2018 can be retrospectively equipped with DynActive. The cost of retrofitting can be paid back through fuel savings in just six to 12 months.

At the heart of DynActive Shifting is an intelligent algorithm that monitors, learns from and responds to vehicle behaviour. This capability is a breakthrough because before now, gear-shift points had to be pre- programmed at fixed engine speeds. With FuelSense 2.0, these points were chosen from a table of options to give a desirable trade-off between fuel economy and performance according to vehicle-type and duty-cycle. Now, however, proprietary software enhancements allow an infinitely variable combination of shift points. This means that each individual vehicle’s gear- shifting strategy is automatically customised and continually refined as the vehicle moves along the road.

DynActive Shifting assesses and responds to factors such as vehicle weight, road gradient, throttle use and the frequency of stop-starts. To the driver, the alterations are imperceptible, but to the accounts department, the reduced expenditure on fuel costs would be evident on the balance sheet.

Ashley Brooks, UK & ROI Area Director at Allison Transmission, commented, “With the original FuelSense software, the transmission had a series of fixed shifting points. What FuelSense 2.0 with DynActive Shifting provides is an infinitely variable combination of shift points. It uses a learning algorithm that locates the ideal balance of fuel economy and performance at any given time. If you look at it the way you might look at a fuel map, what it is constantly searching for is what is known as the sweet spot. It takes into account factors such as input power and torque, and whether the vehicle is ascending or descending a hill. Something else that is included in the equation is whether the vehicle is empty, full, or only partially-full; and this can vary significantly throughout the duty cycle.”

DynActive Shifting is integrated in all three variations of FuelSense 2.0, plus two new options which provide further incremental fuel savings. One of these options is the Plus Package, which adds Neutral-at-Stop technology. This reduces the load on the engine during low-speed coasting and when the vehicle is stopped, which in turn reduces engine heat, emissions and fuel consumption by an additional 1%. The other option, the Max Package, features customisable Acceleration Rate Management. This mitigates aggressive driving by automatically controlling engine torque, but if the vehicle is unable to reach the pre-calibrated acceleration rate – for example, when carrying a heavy load or ascending a gradient – full engine torque is instantly made accessible. This additional method of automatically balancing performance and economy provides approximately 1% more in fuel savings.


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