This year’s edition of the Advanced Clean Transportation Expo featured a more balanced range of driveline technologies, from battery and fuel cell electric at one end of the scale to propane, natural gas, and hydrogen combustion at the other. However, decarbonising the internal combustion engine is not as simple as replacing diesel with a different fuel; the different combustion characteristics of natural gas and hydrogen require alterations be made to the engine so that it works optimally with the new fuel type. One company which has thought long and hard about how to make these necessary tweaks is Eaton Corp. Scott Adams, who is senior vice president of technology and global products for Eaton’s Mobility Group, guided Truck & Bus Builder through the company’s portfolio, showing cutting-edge prototypes as well as its established range of power management technologies.

After attending the Advanced Clean Transportation Expo in the past two years, we were of the view that the USA may catch up with Europe to become the world’s largest electric vehicle market after China. Following the 2025 edition of the ACT Expo – held between 28 April and 1 May in Anaheim, California – I now have serious doubts about how long it will take for America to overtake Europe, if it happens at all. There was a palpable shift away from electric vehicles in favour of alternatives such as natural gas, propane, and hybrid vehicles. Once the stars of the show, these options faded into the background when California’s zero emission vehicle mandate passed into law. Now, the progressive state has repealed the mandate, after the Environmental Protection Agency in January 2025 withdrew the waiver which allowed California to enforce zero emission quotas on fleets; consequently, the low-emission alternatives to diesel and electric are enjoying a revival of interest from many kinds of customer.

The two companies announced they would work together to develop a 4x2 prototype heavy truck with a fuel cell driveline supplied by Symbio.

Hyliion’s founder and CEO, Thomas Healy, told show delegates that the company has exited the EV powertrain market and is now focused on the “distributed power networks of the future”, where charging operators and data centres will make their power “at the end location” rather than depending on the grid.

Following on from an agreement signed last year to develop a self-driving tractor, Kalmar and Forterra are now in the second round of tests of their jointly developed solution.

The German company used the show to present two new products: its upcoming ‘Traxon 2 Hybrid’ powertrain, making its North American market debut; and a third-generation air compressor for the global electric vehicle market.

The American startup announced a partnership with the Japanese giant for the supply of cylindrical lithium-ion ‘2170’ cells, offering an energy density above 800 watt-hours per litre.

With a maximum battery capacity of 625 kilowatt hours, the Kenworth T880E has a range exceeding 250 miles; the advertised range of the Peterbilt Model 567E is the same, with a re-charging time as low as two hours.

The ‘eRH Series’ is a battery electric truck designed to meet the requirements of regional haul and drayage fleets, offering a range of up to 300 miles.

The hope is that these autonomous operations will stimulate the further expansion of fuel infrastructure for hydrogen trucks, producing a “self-reinforcing cycle of vehicle adoption, infrastructure development, and lower operational costs per unit”.

GSBC is Bendix’s electronic braking system technology for medium- to heavy-duty trucks and school buses.

Dubbed ‘Eco Nex Technology’, the box body on display at the show demonstrated Wabash’s capabilities in bringing down weight and cost in its truck bodies.