Stop/start engine tech: Volvo Trucks unveils system for heavy-duty trucks

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• How the downhill engine stop/start actually saves fuel
• Technical roots: an upgrade to I-See and I-Roll
  • Key triggers and limits
• Expected savings and real-world impact
• Which trucks will get the new feature and when
• Where this fits in Volvo’s broader low-emission strategy
• Benefits for fleet operators and sustainability goals

Volvo Trucks says it has created a first-of-its-kind stop/start system for heavy-duty trucks that can cut fuel use and tailpipe CO2 when the road tilts downwards. The feature is built on the firm’s existing route-aware systems and will briefly shut the engine off under certain conditions to save fuel without affecting driveability.

How the downhill engine stop/start actually saves fuel

The system constantly analyses route data and road curvature to spot upcoming descents. When conditions are met, the truck’s engine is temporarily switched off while coasting.

• Zero fuel consumption while the engine is stopped, which also means no tailpipe CO2 during that interval.
• Activation happens only at higher speeds, so drivability and safety remain priorities.
• The feature is designed to work seamlessly with cruise control and other driver aids.

Technical roots: an upgrade to I-See and I-Roll

Volvo engineered the new feature on top of its I-See and I-Roll platforms. Those systems already use map and terrain data to optimise gear choice and rolling behaviour. The stop/start logic adds an extra layer by predicting downhill windows where the engine can be cut without impacting momentum.

Key triggers and limits

• The function engages at speeds above 60 km/h.
• Topography and ambient temperature affect when it can operate.
• Safety and emissions rules are respected; the engine restarts automatically when needed.

Expected savings and real-world impact

Volvo projects the addition will deliver incremental reductions on top of the benefits from I-See and I-Roll. In the right terrain and weather, the company estimates up to a one percent improvement in fuel use and CO2 emissions.

• Small per-trip gains add up across fleets and long routes.
• Lower fuel use also reduces operating costs for truck operators.
• Combined with other measures, the system contributes to larger fleet-level emissions cuts.

Which trucks will get the new feature and when

The stop/start upgrade will be offered for the Volvo FH and the aerodynamic FH Aero. It is tailored for the 13-litre diesel powertrain and will be available to order from November 2025.

Where this fits in Volvo’s broader low-emission strategy

Volvo Trucks frames the innovation as part of a multi-track decarbonization plan. The company continues to develop:

• Combustion engines compatible with renewable fuels.
• Battery-electric trucks for zero-emission urban and regional haulage.
• Fuel-cell electric vehicles for long-range applications.

A senior product manager at Volvo emphasised that improving internal combustion efficiency remains a practical step while alternative powertrains scale up. The new stop/start system is one example of incremental gains that lower emissions now.

Benefits for fleet operators and sustainability goals

Fleet managers can expect modest fuel savings per vehicle that compound across fleets. The feature reduces running costs and helps meet corporate sustainability targets without changing driving routines.

• Minimal driver interaction required.
• Works with existing Volvo driver assistance tools.
• Supports emission reduction targets during the transition to zero-emission trucks.