Fuel Economy Converter

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In this age of environmental consciousness and fluctuating fuel prices, understanding your vehicle’s fuel economy is more important than ever. This article delves into fuel economy conversions, providing insights into various unit conversions and offering practical tips on maximising your vehicle’s fuel efficiency. We’ll cover everything from how to convert miles per gallon (MPG) to litres per 100 kilometres (L/100km), to figuring out fuel consumption for various engine sizes.

Introduction to the MPG Converter

Imagine ordering a car from abroad or traveling to a country with different fuel economy units; the differences can be quite significant. That’s where a Miles Per Gallon (MPG) converter comes in handy. This tool allows you to swap between three main fuel economy units effortlessly:

  1. Miles per US gallon
  2. Miles per UK gallon
  3. Liters per 100 kilometers

Remember, these units are inversely proportional; as one decreases, the other increases, and vice versa. A fuel-efficient car consumes less fuel per distance travelled but can cover many miles on a single gallon. Using a tool like this and a gas calculator, which calculates the total cost of a car trip based on mileage, distance, and gas price, is immensely beneficial.

Understanding Fuel Economy Conversion

Fuel economy is the relationship between the distance a vehicle travels and the amount of fuel it consumes. It’s crucial to note the difference between US gallons and Imperial gallons as they represent distinct values. US gallons are commonly used in the United States and parts of the Caribbean and Latin America. In contrast, you might encounter the Imperial gallon in Commonwealth countries like the United Kingdom and Canada. The majority of the rest of the world uses liters per 100 kilometers.

Here’s where it gets interesting:

  • With miles per gallon (either US or Imperial), the higher the value, the more fuel-efficient the vehicle.
  • With liters per 100 kilometers, a lower value indicates better fuel efficiency and, consequently, smaller gas bills.

These are the basics of fuel economy conversion. If you’re interested in delving deeper, check out our speed calculator and the acceleration calculator, which explore the relationships between time, distance, speed, and acceleration.

Liters per 100km to Miles per gallon – L/100KM TO MPG

L/100kmMPG (US)MPG (UK)Km/L

Miles per gallon to Liters per 100km – MPG TO L/100KM

MPG (US)L/100kmKm/LMPG (UK)

Deep Diving into Related Topics

Fuel efficiency can also denote thermal efficiency – converting energy contained in fuel to kinetic energy or work. Increased fuel efficiency is incredibly beneficial for non-transportation applications, such as industries dealing with combustion or fossil fuel power plants.

Moreover, while the thermal efficiency of petroleum engines has improved in recent decades, this does not always translate to better fuel economy. For instance, people in developed countries often purchase larger and heavier cars, negating potential fuel economy gains.

Frequently Asked Questions

1. How can I improve fuel economy?

Here are a few tips:

  • Drive around 60–65 mph (95–100 km/h). Cars consume fuel more efficiently at these speeds.
  • Ensure your tires are properly inflated.
  • At speeds above 50 mph (80 km/h), close the windows and use the AC to reduce wind resistance and fuel consumption.

2. What is a good fuel economy?

The metrics for measuring fuel economy differ:

  • When using liters per 100 km, “the lower, the better.”
  • With the English metric system (miles per gallon), “the higher, the better.”
  • Popular car blogs say anything less than 6 liters per 100 km is excellent, which equals 39.2 US mpg using a fuel conversion calculator.

3. How to find out the fuel economy of my car?

Follow these steps:

  • Set the odometer to zero and note the fuel tank needle’s position.
  • Fill the tank, noting how many gallons you’ve added. Check the needle again.
  • Drive until the needle returns to its initial position, indicating you’ve consumed the gas added in step 2.
  • Divide the miles driven by the spent gallons. That’s your fuel economy in mpg.

4. How to convert fuel economy from US mpg to liters per km?

Use this method:

  • Start with US mpg (miles per US gallon). Multiply it by 1.609 to convert miles to kilometers.
  • Divide the result by 3.78 to convert US gallons to liters.
  • You now have fuel economy in km per liter. Multiply by 100 for the liters per 100 km measure.

The Math Behind Fuel Economy Conversion

To see how these conversions work in practice, consider the following example:

  • 1 mpg (US) is equal to 235.21 L/100km

We can represent this as a table:

Miles per gallon (mpg)Liters per 100 km (l/100km)

Engines and Fuel Consumption

Various factors influence fuel consumption, such as engine size and type. Here are some examples:

  1. 3.5-liter engine fuel consumption per km
  2. 2.4-liter engine fuel consumption per km
  3. 2.5-liter engine fuel consumption per km
  4. 1.5-liter engine fuel consumption per km
  5. 3.0-liter engine fuel consumption per km

Each engine size will have a different consumption rate, which you can calculate using a mpg to l/100km converter.


Whether you’re a car enthusiast, an eco-conscious driver, or simply looking to save on fuel costs, understanding fuel economy is beneficial. This guide has armed you with a fundamental understanding of the various units of fuel economy, how to convert between them, and how to determine your vehicle’s fuel efficiency.

Armed with this knowledge, you’re now better prepared to make informed decisions about fuel consumption, be it for purchasing a new vehicle or modifying your driving habits for improved efficiency.

Stay tuned for our upcoming articles where we will explore more about engines, their performance, and how to make the most of your car’s fuel efficiency with the help of various calculators and tools. Until then, safe and efficient driving!

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