The Volvo FH is from now on available with a start-stop function. Additional fuel savings of up to 1% are possible, according to Volvo Trucks. Engine shutdown is subject to certain conditions.
The Volvo FH / FH Aero will be available with a start-stop function, as an extension of the I-Roll system (coasting function). This was announced by Volvo Trucks. The Swedish truck manufacturer is the first to apply this fuel-saving technology in trucks.
Volvo Trucks’ latest addition is based on the existing I-See and I-Roll technologies. The new start-stop engine function continuously monitors road conditions, such as gradients and curves. If an impending downhill gradient is detected on the route, the engine is temporarily switched off. No fuel is consumed during this time, and therefore no exhaust emissions are produced.
The new start-stop engine functionality is activated at speeds above 60 km/h. Depending on conditions, such as topography and ambient temperature, this can deliver up to 1% additional fuel and CO2 savings, on top of the savings already achieved.
How exactly does this start-stop function work? If the aforementioned conditions occur and the stop function is activated, the engine stops and the clutch is disengaged, allowing the truck to continue rolling in neutral. If the downward slope is too steep, the stop function will not engage, so the vehicle can decelerate using the engine compression (and possibly engine braking). Essentially, the vehicle uses the moments when I-Roll shifts to neutral to also switch off the engine.
But is it actually useful to completely shut down the engine while driving? After all, many functions are linked to the engine. We asked Volvo Trucks this question. The steering pump is driven by the gearbox and continues to operate when the engine is switched off. The alternator, water pump, and air conditioning compressor are no longer operational because the engine is switched off. If the on-board voltage, coolant temperature, or cabin climate are not optimal, the engine will not switch off. All of this is continuously monitored by the system and factored into the decision whether or not to switch off the engine. In short: engine shutdown only occurs when it is responsible and safe to do so, and when it increases efficiency. Naturally, this function was tested as extensively as possible before its official introduction, Volvo Trucks explains.
The stop-start function is available on the Volvo FH and Volvo FH Aero with a 13-liter diesel engine since November 2025.
(Volvo is pursuing a three-pillar strategy for future engine development: the most efficient combustion engines possible running on renewable fuels (such as synthetic diesel), battery-electric trucks, and hydrogen trucks.)
