Environmental and Fuel-Efficient Driving
Fuel-efficient driving is scored as a technique, not an attitude. The exam looks for smooth control, correct gear choice, planned routes and maintained equipment - the same habits that cut brake and tyre wear.
Where the fuel goes
- Hard acceleration and late braking burn fuel and brake linings; anticipation is free.
- Speed is the biggest single factor: pushing from 90 to 110 km/h can add a fifth or more to fuel consumption because drag rises with the square of speed.
- Idling wastes fuel and glazes engines; switch off if you expect to stand for more than about a minute.
- Under-inflated tyres, wrong wheel alignment, a clogged air filter and a dragging brake all quietly cost fuel.
- Aerodynamics matter at truck height: a fitted cab roof fairing, tight side skirts and a well-secured tarpaulin reduce drag.
Driving technique
- Accelerate firmly but briefly to cruising speed, then hold it steadily; use cruise control on level ground.
- Keep the engine in its efficient band and let the retarder manage descents - modern engines cut fuel entirely on overrun.
- Plan the route: avoid congestion, combine loads, avoid empty running where the operator can plan a backhaul.
- Black smoke under load signals over-fuelling or an injector fault, not just wasted fuel; it also fails emissions checks at technical inspection.
Worked example
A 300 km run at 35 L/100 km uses 105 L. Careful driving brings it to 32 L/100 km. Reasoning: 300 × 0.32 = 96 L, a saving of 9 L per trip - with less brake wear and lower tyre temperatures as a bonus. The gain came from steady speed, early lifts off the accelerator and correct tyre pressures.
Traps that cost marks
Coasting in neutral to save fuel; believing a warm engine needs a long idle; ignoring tyre pressures between services.