Hanover, Germany, May 12, 2021. The electrification of urban delivery vehicles has huge potential. Using electric trucks for delivery work is helping to bring about a substantial reduction in CO2 emissions and noise pollution in downtown areas. However, before fleets of electric vehicles can operate, certain elements must first be in place – a new charging infrastructure, for example, as well as different power networks, operating procedures and, not least, the right tires. So as they take the company’s range of products for the electric mobility segment forward, the tire developers at Continental have been looking closely at their customers’ needs. The company has been involved in field trials of electric trucks for several years now, in the process collecting information for a commercial vehicle tire specially adapted to vehicles with electric drive. The robust Conti Hybrid tire for regional applications is currently racking up the miles.
In late 2018, the Stiegl brewery in Austria added an electric truck from MAN to its fleet. Since then, its Conti Hybrid HS3 and HD3 tires have covered more than 23,000 kilometers. The truck is on the road eight hours every day in downtown Salzburg and within an approximately 50-kilometer radius of the city. “The Continental tires perform exceptionally well in all driving situations,” reports Stiegl driver Dominik Lackner. “It’s great to be able to rely on so much grip when pulling away. I can get away from traffic lights as quickly as the car next to me, which is a whole new feeling.” This is one of the important pieces of feedback gathered regularly by Kurt Bergmüller, head of sales at Continental Reifen Austria GmbH. “We monitor the condition of the tires and note what drivers and fleet managers have to say about them. I’m pleased to say that our tires have the performance and potential required for use on electric vehicles. That means they are playing a major role in lowering noise levels and pollutant emissions, as well as helping to keep fossil fuels in the ground.”
The Stiegl brewery is one of eight Austrian companies in the trade, logistics and production sectors with which MAN launched intensive field trials of all-electric trucks in regular logistics operations in 2018. The firms are part of the CNL consortium, a currently unique Europe-wide initiative of 18 Austrian companies working together under the aegis of the University of Vienna on what will be a key issue in years to come: sustainable logistics.
The development of tires for electric urban and regional delivery trucks represents a technological challenge. “This new drive system has prompted us to come up with new development concepts,” says Hinnerk Kaiser, head of tire development at Continental. “Developing tires for electric vehicles is particularly demanding in technical terms because they have to withstand higher torque, generate as little rolling noise as possible, and be able to carry what are still quite heavy batteries. And they have to do so while delivering the same mileage and ensuring the same level of safety.” Delivery trucks frequently have to negotiate stop-start traffic and drive over curbs, added to which, as Kaiser adds: “Tires on electric trucks are subjected to higher torque when pulling away and accelerating.” Then there is deceleration to consider: When the vehicle brakes, its electric motor generates power for charging the battery. This recuperation process further increases the workload for the drive axle tires. And finally, there is the special focus on rolling noise in downtown areas: “This is where vehicles need to be particularly quiet to make sure the comfort-enhancing benefits of the electric motor aren’t negated by tire noise,” says Kaiser.
For the CNL field trial, Conti Hybrid HD3 and HS3 tires were fitted to the MAN eTGM truck. “We chose the HD3 for the test as it’s our specialist tire for regional transportation, offers high mileage and has a robust tread,” explains Kaiser. “The Conti Hybrid HS3 is likewise designed for regional duties and offers high mileage and good wet performance over its full lifetime. All in all, these are the attributes with which we can currently help electric trucks most effectively in urban traffic.”
New drive systems and vehicle concepts are changing the demands placed on tires and driving the need for new development concepts. For many years, Continental has been gathering valuable real-world experience through development partnerships. “Resolving conflicting goals – especially mileage versus braking and handling performance – is technically demanding,” explains Hinnerk Kaiser. “This presents us with new challenges, but we’re definitely not going to be making any compromises when it comes to robustness and braking performance.” Given the strong demand from municipalities and mass transit operators for emission-free electric vehicle fleets and the rapid development of the electric mobility segment, there is also a growing need for the right tires.