Fuel saving for trucks: what actually lowers diesel consumption

1. Tyre pressure: the cheapest win

Under-inflated tyres raise rolling resistance. On a tractor-trailer, a systematic 1 bar shortfall across all axles typically adds several percent to consumption and shortens tyre life at the same time.

Make pressure checks a fixed weekly task rather than a reaction to a problem. Tyre pressure monitoring pays for itself within the first year on fleets above 20 vehicles.

• Check cold tyres before departure.
• Log values per vehicle — deviations reveal slow leaks.
• Specify low rolling resistance tyres at the next replacement.

2. Driver behaviour and coaching

The gap between the best and worst driver on the same route in the same truck is routinely 10–15% of fuel use. Harsh acceleration, late braking, excessive kick-down and cruising above the economical speed explain most of it.

Coaching only sticks when it is paired with feedback. A monthly per-driver report with a clear target keeps the result; a one-off training session fades within two or three months.

• Keep engine revs in the economy band and use the vehicle's momentum.
• Dropping from 90 to 85 km/h produces a measurable saving on long runs.
• Limit idling — every idle hour burns roughly 2–3 litres.

3. Aerodynamics and loading

Above 60 km/h, air resistance dominates. Roof deflectors, side skirts and a correctly set tractor-trailer gap make a measurable difference on motorways.

Empty running is pure loss. Route planning that removes empty kilometres often saves more than every technical measure combined.

4. Maintenance that shows up in litres

A clogged air filter, worn injectors, poor wheel alignment and a faulty thermostat quietly raise consumption. None of these trigger a dashboard warning — they only appear in the fuel log.

• Respect air and fuel filter intervals.
• Bench-test injector spray patterns.
• Re-check alignment after every kerb or pothole strike.

5. Fuel saving technology with measured results

Once the organisational measures are exhausted, what remains is combustion quality. The Comet Fuel Saving System (CFSS) treats fuel before it enters the combustion chamber, enabling more complete combustion and less unburnt fuel leaving through the exhaust.

Methodology matters more than the claim: consumption is measured before and after installation, on the same routes and the same vehicles, using litres dispensed at the pump against distance or engine hours. The contracted minimum on liquid fuels is 7%, while measured results are most often 8–12%.

• Measure for at least 90 days to cover seasons and route types.
• Keep a control group without the system to isolate external effects.
• Report per vehicle, not as a fleet average — averages hide outliers.