Heavy haulage trucks and fuel savings are not usually found in the same sentence. However, Scania have put together a transmission that could improve fuel consumption with a transmission robust enough for the job and able to pull away with the largest of loads.

Heavy G-Range Transmissions

Scania’s G25CM and G33CM range is now joined by two new members, with an “H” (for Heavy) in their designations. G25CH and G33CH share all the virtues and properties of their siblings. But by adding a sturdier planetary gear, Scania is now offering a combination of robustness, smooth gear shifting and fuel efficiency.

“By adding these options, we are making it even clearer that our XT range and our mining offer mean serious business,” says Stefan Dorski, Senior Vice President and Head of Scania Trucks. “Their ability to deal with the kind of challenges trucks in heavy-duty operations are facing will make a difference regarding uptime and R&M cost for customers.”

Scania’s latest generation of automated gearboxes is renowned for its technological excellence. When they were introduced in 2020, these gearboxes brought best-in-class capabilities such as increased fuel and transport efficiency, smooth and fast gear shifting and reduced weight. One of their main virtues is the wide gear ratio spread that (together with the relevant rear axle gearing) makes sure that the engine can work on low revs while also providing its full torque.

“Scania’s heavy-duty offer has never been stronger,” says Eduardo Landeo, Product Manager at Scania Trucks. “Not only do we offer a full line-up of engine options but this addition, in combination with our wide axle range, means we can cater even better to the most demanding and heavy applications in the trucking industry.”

The optimal balance

Heavy-duty truck combinations with high gross train weights typically use 6×4 rear bogie axles with “short” gearing (3.5:1 and higher; sometimes much higher). In hilly conditions or with high rolling resistance, this puts a lot of stress on the outgoing axle in the gearbox. The short gearing, typically in combination with hub reduction axles, is beneficial for take-off and starting the vehicle, making the truck more powerful but also leading to higher engine revs at cruising speed.

Since Scania strives for low engine revs and favourable fuel consumption, the trick is to find the optimal balance between the rear axle gearing and the actual operation. The properties of Scania’s heavy-duty gearboxes mean that more trucks can now use a faster gearing while still having all the margins on their side.

All aluminium, quiet and efficient

The G-range for Scania Opticruise was introduced in 2020 and was 60 kg lighter than its predecessor, due to its all-aluminium housing and smaller dimension, and it also offered lowered noise levels.

The G-range helps operators save fuel through its reduced internal friction and by only having two synchronisers, since it uses pneumatic actuators and shaft brakes (three in total). When working with a smart engine management system, such the Super-based powertrain, the G-range is instrumental for swift and accurate gear shifting.

G25CH and G33CH Scania Transmission
The trick is to find the optimal balance between the rear axle gearing and the actual operation