Fuel Efficiency Calculator

Calculate your vehicle's fuel efficiency using distance driven and fuel consumed. Check km/L, L/100km, and cost per km instantly, and compare with average efficiency by vehicle type.

How to Use

Step 1: Select Mode

'Calculate Efficiency' mode computes actual fuel efficiency from distance and fuel used. 'Trip Cost Calculator' mode estimates fuel needed and cost for a trip based on your car's efficiency.

Step 2: Enter Information

For efficiency calculation: enter total distance driven (km), fuel consumed (L), and fuel price (KRW/L). For trip cost: enter trip distance, your car's average efficiency, and current fuel price.

Step 3: Use Quick Presets

If you don't know the fuel price, click the quick preset buttons. Average 2024 prices are auto-filled: Gasoline ~1,650 KRW/L, Diesel ~1,500 KRW/L, LPG ~950 KRW/L.

Step 4: Check Results

Click Calculate to see km/L, L/100km, and cost per km. The comparison table shows how your car compares to average efficiency of sedans, SUVs, compact cars, and more.

About Fuel Efficiency Calculator

The Fuel Efficiency Calculator is a free tool that computes your actual fuel efficiency (km/L) from distance driven and fuel consumed. Fuel efficiency indicates how many kilometers you can drive per liter of fuel, serving as the most fundamental measure of vehicle fuel economy.

Real-World Use Cases

Check Actual Efficiency

Reset your trip meter after refueling, record distance and fuel amount at next refuel to calculate actual efficiency. Compare with manufacturer's rated efficiency to check vehicle condition.

Estimate Long-Distance Trip Cost

For a 400km Seoul-to-Busan trip with 12km/L efficiency and 1,650 KRW/L gasoline, total fuel cost is about 55,000 KRW. Use this for trip budget planning.

Compare Fuel Types

Compare LPG (10km/L, 950 KRW/L) vs gasoline (12km/L, 1,650 KRW/L) vehicles. LPG is more economical for the same distance despite lower efficiency.

Vehicle Purchase Comparison

When buying a new car, compare efficiency across models to calculate annual fuel costs and evaluate total cost of ownership (TCO).

Fuel Efficiency Tips

  • Avoid sudden acceleration and braking. Eco-driving habits can improve efficiency by up to 20%.
  • Maintain proper tire pressure. Low tire pressure can reduce efficiency by up to 3%.
  • Reduce unnecessary cargo. Every 100kg increase reduces efficiency by about 5%.
  • Minimize air conditioning use. A/C can reduce efficiency by 10-20%.
  • Regularly replace engine oil and air filters. Old filters can reduce efficiency by 5% or more.
  • Maintain economical speed (80-100km/h) on highways. Higher speeds increase air resistance.
  • Minimize idling. Turn off the engine when stopped for more than 10 seconds.

Average Fuel Efficiency by Vehicle Type (2024)

Vehicle TypeAverage Efficiency (km/L)Notes
Compact16Morning, Spark, etc.
Compact Sedan14Avante, K3, etc.
Mid-size Sedan12Sonata, K5, etc.
Compact SUV13Kona, Seltos, etc.
Mid-size SUV11Tucson, Sportage, etc.
Large SUV9Palisade, Mohave, etc.
Hybrid20Ioniq, Niro HEV, etc.

FAQ

What's the difference between km/L and L/100km?

km/L shows kilometers per liter (higher is better), commonly used in Korea. L/100km shows liters needed per 100km (lower is better), used as the international standard. For example, 12km/L equals about 8.3L/100km.

Why is actual efficiency lower than rated?

Rated efficiency is measured under standardized lab conditions. Real-world driving is affected by traffic, driving habits, A/C use, cargo weight, and tire pressure. Actual efficiency is typically 10-30% lower than rated.

How do I measure efficiency accurately?

Use the 'full-to-full' method: fill up completely, reset trip meter, drive until next fill-up, fill up again and note the fuel amount. Distance / Fuel = actual efficiency. Repeat 3-4 times for accuracy.

How do I calculate hybrid vehicle efficiency?

Hybrid vehicles use the same calculation: distance / fuel consumed. However, efficiency varies more by driving pattern since hybrids use both electric motor and engine.

Does efficiency change by season?

Yes, significantly. Summer A/C use reduces efficiency 10-20%. Winter heating and cold temperatures can reduce it 15-30%. Spring and fall provide the best efficiency.

Diesel vs gasoline efficiency?

Diesel vehicles are typically 20-30% more efficient than gasoline. Diesel engines have higher compression ratios and thermal efficiency. Combined with lower diesel prices, fuel cost savings are significant.

What to check if efficiency suddenly drops?

Check: (1) tire pressure, (2) air filter, (3) spark plugs, (4) oxygen sensor, (5) brake pads, (6) engine oil. Visit a mechanic for diagnosis.

Notice

  • Actual efficiency varies significantly by driving conditions, habits, and vehicle condition.
  • Fuel prices vary by region and station. Use as reference only.
  • Average efficiency values are general 2024 figures; individual vehicles may differ.
  • For accurate measurement, repeat at least 3 times and average the results.

This calculator is provided for informational purposes only.

Results are estimates and may differ from actual amounts.

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