Diesel Consumption in Truck Calculator | Get All the Answers and More

On average, a heavy-duty commercial truck burns 0.30 to 0.40 litres of diesel per kilometre (which translates to 30 to 40 L/100km) under standard highway conditions. For lighter delivery trucks, this figure drops to roughly 0.15 to 0.25 litres per kilometre (15 to 25 L/100km).

The amount of diesel you burn while idling depends on the type of car you’re driving, but you burn anywhere between 0.6 (smaller cars) and 4.0 (heavy-duty trucks) litres per hour while idling. Remember, fuel loss is just one component that impacts your finances. Idling can also cause engine and parts damage, resulting in higher costs.

You can quickly calculate the diesel cost per km by first taking the fuel consumption rate and dividing it by 100. Then multiply this answer by the diesel price per litre. 

For example: 7.0 L/100 km ÷ 100 = 0.07 L/km

0.07 × R23.50/L = R1.65 per km

Yes, idling is generally worse than stop-and-go, although it depends on your context and reasoning. Idling is certainly worse from a fuel consumption perspective, because it uses up more fuel while it’s not going anywhere. At least with stop-and-go, there’s movement and productivity as an outcome. 

The average fuel economy of a heavy-duty truck is roughly 30 to 50 litres per 100 kilometres. The exact fuel economy depends on factors like the make and model of the truck, the landscape it’s travelling through, cargo weight, driver behaviour, and vehicle condition.

With a fleet management system, you can save on diesel costs by:

• Taking advantage of route optimisation to get the best, most efficient routes
• Keeping a close eye on fuel consumption patterns so you can identify the problems and quickly fix them
• Monitoring driver behaviour, because poor driving habits waste fuel
• Using specialised fuel sensors to detect irregularities like fuel theft

Yes, fuel consumption is calculated the same way for petrol and diesel vehicles. But it’s important to recognise that diesel engines are typically more efficient as a fuel type than petrol, so the fuel consumption outcomes won’t be the same.

Factors that can cause a truck to use more diesel than expected include:

• A poorly maintained truck, which will use more fuel just to work optimally
• Unnecessarily heavy cargo loads 
• Aggressive, fuel-wasting driving behaviours 
• Low-pressure tyres, which uses more fuel just to move the vehicle
• Poor route planning
• Not using a fleet or fuel system

According to the Engine Technology Forum and Truckstop, the ideal driving speed for optimal diesel fuel economy in a truck is roughly 90 km per hour. Ideal driving speeds aren’t enough though; drivers must remember to pair optimal speeds with defensive driving habits for the best results. 

Low tyre pressure has a negative impact on fuel efficiency because low tyres force your engine to work harder just for the vehicle to move. This means you’re using far more fuel than is necessary while putting yourself at risk; the wheels could drag along the road or could blow out.

According to KwikFit, air conditioning (AC) consumes about 8% to 10% more fuel, otherwise about 0.2 to 0.4 litres per hour. These numbers could easily fluctuate based on weather, the condition of the engine, the exact size of the truck and other factors.