Tracking diesel consumption before a long trip can help drivers control costs, plan refueling stops, and reduce the risk of running out of fuel on routes with few gas stations. It also provides a quick warning sign if engine efficiency has started to drop.
This matters even more on intercity roads across Sumatra, where steep climbs, descents, mixed traffic, heavy vehicles, and cargo loads can make diesel use noticeably higher than in ordinary city driving.
How to calculate fuel consumption
The simplest method is to fill the tank to the same level, note the odometer or trip meter, then refill to full after covering a certain distance and record how many liters were needed.
The formula is straightforward: divide the distance traveled by the amount of fuel used. If a diesel car covers 480 kilometers and needs 40 liters to refill, the result is about 12 kilometers per liter.
That figure helps drivers estimate fuel needs for the next route. For example, a trip from Palembang to Bandar Lampung, which is about 370 kilometers, would require around 31 liters if the average consumption is 12 kilometers per liter.
| Calculation Example | Distance | Fuel Used | Result |
|---|---|---|---|
| Diesel car | 480 km | 40 liters | 12 km/liter |
| Palembang to Bandar Lampung route | 370 km | about 31 liters | based on 12 km/liter consumption |
Why the number can change from trip to trip
The result is not always identical on every journey. Road conditions, vehicle load, driving speed, and tire pressure are among the fastest factors to affect efficiency.
A car carrying more passengers or cargo usually needs more power. A roof box or items placed on the roof can also increase wind resistance and raise fuel use.
Steady speed is usually more efficient than repeated acceleration and hard braking. On vehicles equipped with it, cruise control can also help maintain efficiency on toll roads.
Low tire pressure is often overlooked, yet it increases rolling resistance and forces the engine to work harder. Tire pressure should be matched to the recommendation in the owner’s manual or on the driver’s door sticker.
Maintenance and driving habits also matter
A dirty air filter, clogged injectors, oil that has passed its service life, and suboptimal turbo pressure can all increase fuel consumption. Official service guidance from various diesel car manufacturers stresses the importance of regular maintenance to keep efficiency stable.
Fuel must also match the vehicle’s specification. The Ministry of Energy and Mineral Resources has stated that using the right fuel and driving efficiently can help improve fuel consumption.
During the trip, drivers are advised to use momentum on descents and avoid leaving the engine idling for too long. Idling still burns fuel even when the car is not moving.
If fuel use suddenly becomes much worse than usual, the vehicle should be checked. A drop in efficiency may be linked to the combustion system, injectors, turbocharger, engine sensors, or other components that need workshop inspection.
sumeks.disway.id also noted that regularly monitoring fuel consumption is not only about saving money, but also about preparing for long-distance travel. With routine calculations, drivers can plan fuel stops more easily before entering stretches where gas stations are far apart.