Should I use the manufacturer's consumption figure?

No — measure your own. Brim the tank, reset the trip meter, drive as you normally do for a few hundred kilometres, then refill and divide the litres added by the kilometres travelled. That number is usually 10–20% worse than the official figure and it is the one that predicts your actual bills.

How much does driving slower really save?

More than people expect on motorways. Dropping from 130 to 110 km/h typically cuts consumption by 20% or so, because drag scales with the square of speed. On the 450 km example that is roughly 40 saved for about 40 minutes more travel time.

Fuel Cost Calculator

Calculate how much you'll spend on fuel for your trip. Enter distance, fuel efficiency, and gas price.

Unit

Distance (km)

Fuel efficiency (L/100km)

Price per liter

How to Reduce Fuel Costs

Fuel is a significant expense for every driver. There are many ways to reduce fuel consumption and save money on fueling. Conscious driving and regular car maintenance can bring tangible results in the form of lower costs.

Economical Driving – Less Fuel, More Savings

Smooth driving without sudden acceleration and braking can reduce fuel consumption by 20-30%. Maintain a constant speed on the highway (optimally 90-110 km/h) and use cruise control. Avoid idling – if you are stopped for more than a minute, it is better to turn off the engine. Plan your route in advance to avoid traffic and detours.

Checking Technical Condition

Under-inflated tires increase rolling resistance and fuel consumption by a few percent. Regularly check tire pressure and adjust it for vehicle load. Faulty spark plugs, dirty air filter, or incorrect oil level can also increase fuel consumption. Annual technical inspection is essential.

Comparing Fuel Prices

Fuel prices vary depending on the station and region. Use fuel price comparison apps to find the cheapest station in your area. Fuel up in the morning or evening – prices are sometimes lower than in the middle of the day. Consider fleet cards or loyalty programs that offer fuel discounts.

What a journey actually costs in fuel

Fuel cost is distance times consumption times price — three numbers, one of which almost everybody guesses wrong. The consumption figure on the manufacturer's brochure is not the one your car achieves.

How it works

Converts distance and consumption into litres burned, then multiplies by the price per litre.
Gives a cost per kilometre, which is the figure worth remembering for future trips.
Splits the total between passengers, for shared journeys.

litres = distance (km) × consumption (L/100km) ÷ 100
cost   = litres × price per litre

cost per km = cost ÷ distance

converting: mpg (UK) = 282.48 ÷ (L/100km)
            7.2 L/100km ≈ 39.2 mpg

Worked example

A 450 km drive in a car averaging 7.2 L/100 km, with fuel at 6.50 per litre, four people sharing.

litres = 450 × 7.2 ÷ 100 = 32.4 L
cost = 32.4 × 6.50 = 210.60
cost per km = 210.60 ÷ 450 = 0.468
split four ways = 52.65 each
return journey doubles it: 64.8 L, 421.20

210.60 one way, or about 47 cents a kilometre. Shared between four that is 52.65 each — comfortably less than a train ticket on most routes, which is why the calculation is worth doing before assuming otherwise.

Reading the result

Use your own observed consumption, not the brochure figure. Official WLTP numbers are measured under controlled conditions and real-world consumption typically runs 10–20% higher. Fill the tank, drive normally, refill, and divide litres by the distance covered.
Speed dominates on long trips. Aerodynamic drag rises with the square of speed, so 130 km/h burns roughly 20–25% more than 110 km/h over the same distance. On a 450 km motorway run that is most of an hour saved for a noticeably larger bill.
Cold engines and short journeys are disproportionately expensive. A car uses far more fuel in the first few kilometres before the engine reaches operating temperature, so urban consumption bears little relation to a motorway average.
Fuel is not the full cost of driving. Tyres, servicing, depreciation and tolls typically add as much again. If you are comparing against public transport, compare on total cost rather than fuel alone.

Common questions

Should I use the manufacturer's consumption figure?: No — measure your own. Brim the tank, reset the trip meter, drive as you normally do for a few hundred kilometres, then refill and divide the litres added by the kilometres travelled. That number is usually 10–20% worse than the official figure and it is the one that predicts your actual bills.
How much does driving slower really save?: More than people expect on motorways. Dropping from 130 to 110 km/h typically cuts consumption by 20% or so, because drag scales with the square of speed. On the 450 km example that is roughly 40 saved for about 40 minutes more travel time.