Everything you need to know about fuel efficiency and costs.
MPG measures how many miles a car can travel on one gallon of fuel. L/100km measures how many liters of fuel the car consumes to travel 100 kilometers. Lower L/100km or higher MPG indicates better efficiency. For international comparisons, convert using 1 L/100km ≈ 235.21 ÷ MPG to keep figures consistent.
They are measured under controlled test cycles to enable fair comparisons between vehicles. Real-world results vary due to driving style, traffic, temperature, terrain, and vehicle load. CarFuelCost.com shows both city and highway consumption where available and encourages using your own long‑term average for precise planning.
Use our calculator to enter the distance and current fuel price, then review the total and per‑km cost. If you know your car’s average consumption, enter that for the most accurate estimate. For multi‑stop trips, sum the distances or run multiple calculations and add the results.
Yes. Under‑inflated tires increase rolling resistance and fuel consumption and can lengthen braking distances. Check tire pressures monthly (including the spare) and before long trips, and adjust when carrying heavy loads per the placard in your door jamb.
Hybrids typically consume far less fuel in city driving thanks to electric assist and regenerative braking, especially in stop‑and‑go traffic. Highway differences may be smaller but are still often favorable. Use CarFuelCost.com to compare combined MPG and estimated annual costs based on your city/highway mix.
Smooth acceleration, anticipating traffic, keeping steady speeds, limiting idling, and observing speed limits can reduce consumption by 10–25% depending on conditions. Remove unnecessary weight and plan routes to avoid congestion. Using cruise control on open roads also helps maintain efficient speeds.
Yes. They increase aerodynamic drag and can raise consumption by 5–15% at highway speeds, sometimes more with large boxes. If possible, carry items inside the vehicle and remove racks when not in use. Choosing lower‑profile accessories can also minimize drag penalties.
Cold weather and frequent short trips increase consumption as engines take longer to reach optimal temperatures and cabins require more heating. Air conditioning adds extra load, especially at low speeds and during hard acceleration. Pre‑conditioning EVs or parking in shade helps reduce HVAC demand.
Compare body type, fuel type, transmission, and tire sizes under similar conditions and payloads. Use combined MPG and L/100km, then weight results by your city vs highway mix to mirror real use. Reviewing tank size, range, and maintenance intervals also provides a fuller ownership picture.
Use your current local price per liter (or per gallon) from a recent fill‑up or a trusted price index. If prices are volatile, run a few scenarios (low/average/high) to see sensitivity. For long‑term budgeting, using a 6–12 month average smooths short‑term spikes.
On flat highways, cruise control can reduce small speed fluctuations and improve efficiency slightly. In hilly terrain it may hold gears longer and increase fuel use; a light foot anticipating climbs and descents can be better. Use it where traffic and terrain allow steady speeds.
Extra weight requires more energy to accelerate, increasing fuel use especially in stop‑and‑go driving. Removing 45–90 kg (100–200 lb) of unnecessary cargo can produce a noticeable improvement for small cars. Roof‑mounted loads add both weight and aerodynamic drag, compounding the effect.
Wider or stickier tires can increase rolling resistance and aerodynamic drag, reducing fuel economy. While they may improve grip and appearance, match tire size and rating to your vehicle’s recommendations. Keeping tires properly inflated and aligned minimizes efficiency losses.
Correct tire pressure, clean air filters, properly functioning oxygen sensors, and fresh spark plugs (for gasoline engines) are key. Address check‑engine lights promptly, as many relate to sensors that affect fuel mixture. Regular oil changes with the specified grade also help maintain efficiency.
