back to articles | July 25, 2022 | Greg Thibodeau

Categories:   Useful Automotive Information   

Understanding Fuel Economy Ratings on Today's Cars

Fuel efficiency refers to the distance covered or travelled in a given amount of fuel. Fuel efficiency is essentially the amount of fuel consumed by a car over a given distance, often measured by a litre per hundred kilometres distance.


Fuel efficiency refers to the distance covered or travelled in a given amount of fuel. Fuel efficiency is essentially the amount of fuel consumed by a car over a given distance, often measured by a litre per hundred kilometres distance.

Fuel economy ratings give reliable information about fuel consumption. This information or fuel economy ratings allow drivers to compare and contrast the fuel efficiency levels of different car models. This, in turn, helps drivers select the most fuel-efficient and the most economical option.

To measure fuel consumption and provide accurate estimates of fuel efficiency levels, oil conglomerates in collaboration with automakers design fuel rating tools to provide reliable and accurate data on fuel consumption and efficiency levels.

The fuel consumption rating tool compares the fuel consumption of discrete automobiles, allowing car owners to select the most fuel-efficient option.

At its very basic level, fuel efficiency is a crucial metric in selecting a car. Let's break it down.

Annual driving average 14,750 km 14,750 km
Fuel economy 4 litres/100 kms 5 litres/100 kms
Litres required 590 litres 590 litres
Fuel cost for the year ($1.25 per litre) $737.50 $921.25

The information above shows that even with a litre difference, the owner of car B will require an additional 147 litres of fuel and incur $183.75 more than his counterpart car A.

These extra expenses come because you selected a car that consumes an extra one litre for every 100 kilometres.

Fuel Economy Ratings

So, with these metrics, you may wonder what qualifies as fuel efficient – then?

For a car to qualify as fuel-efficient, it must have an average of 6 litres per 100 kilometres distance – which also translates to 17 kilometres per litre of fuel.

The first and more important reference is the fuel per litre. And fuel efficiency ratings are set to litres per a hundred kilometres (L/100KM). So, what really qualifies as fuel efficiency is the one with the least amount of fuel consumption per kilometre covered.

Differences in fuel consumption!

Fuel consumption ratings show the fuel consumption if you drive your car safely and when your automobile is in the best shape. Fuel efficiency ratings are standard benchmarks of fuel consumption when everything is constant, including the car's condition; and how it's handled and maintained.

These ratings help you to compare the fuel consumption of different cars so that you can make an informed and educated decision on the car selection.

However, it's hard for a laboratory test to hypothesise or even estimate how much fuel a driver will need. Your vehicle's consumption will vary depending on the condition of your car, your driving styles, and your driving terrain, regardless of your fuel economy ratings.

These factors affect your fuel efficiency ratings:

  • Acceleration. How you accelerate impacts your overall fuel consumption, regardless of the distance you travel. Most increases in fuel consumption rates due to acceleration occur because of increased energy demand. When you accelerate, the vehicle demands more energy and hence more fuel consumption.
  • Speed. How fast you drive affects your consumption levels. Speeding increases fuel consumption and reduces fuel efficiency due to air resistance from the vehicle as well as rolling resistance from the terrain.
  • Vehicle status. The age and condition of your vehicle will ultimately affect its fuel consumption. Older vehicles or poorly maintained automobiles consume a large amount of fuel because of faulty engines, worn-out tires, and generally higher demand for fuel due to the inefficiency of automotive machine parts.
  • Temperature and weather. Cold weather negatively affects fuel economy. Standard fuel consumption is 15% lower at 20°F than it would be at 75°F. During hot temperatures, engines warm up and perform better. Warm air leads to less aerodynamic drag than cold air.
  • Traffic and road conditions. Poor road conditions affect your fuel efficiency due to more friction that demands more fuel (or more energy) to overcome the friction. Traffic may potentially lead to more fuel consumption to keep the engine running during traffic.
  • Air-conditioning. Air-conditioners, chargers, car blankets, electric car jacks, extension cords, and other powered automotive accessories consume fuel and lead to lower fuel-efficiency levels.
  • Vehicle type. All-wheel drive vehicles consume a relatively higher amount of fuel than two-wheel drive vehicles when covering the same distance. Your car selection has a direct impact on your fuel consumption.

Diesel vs. Petrol Debate

Petrol and diesel are common fuel types used in cars today. However, of the two, petrol is commonly used in Australia while the United States uses gasoline fuel or petrol to power their cars.

When comparing diesel and petrol, diesel has relatively more energy, and engines running on diesel enjoy a more efficient engine combustion process. Although both fuels power cars, they have different operational mechanisms, as well as relative advantages and disadvantages.

Benefits of Petrol

Petroleum is highly preferred as a fuel because of its varied benefits. For instance, it's easy to extract petroleum, thus costing relatively cheaper. In addition, it's a high-density fuel, meaning that its combustion occurs at a slower pace. You can convert petrol to CNG if you like. In addition, petroleum is relatively environmentally safer and more sustainable to extract than diesel. Automotives powered by petroleum cost cheaper than those powered by diesel fuel.

Benefits of Diesel

Diesel engines have efficient combustion powers, making them relatively more efficient than petrol-powered engines. Diesel generates more torque (pulling power) than petrol, making them superior options for towing or carrying extremely heavy loads in transportation, construction, logistics, and many other sectors.

Indeed, per litre, diesel contains more torque power than petrol, making it a classic option for pulling heavy loads. In addition, diesel generates less carbon (IV) and other vehicular emissions, making it a more sustainable option.

So, whether you're using petrol or diesel, both fuels have their comparative benefits and are classic options when selecting your dream car. – Powering Your Car Ownership Dreams! is a trusted provider of unbeatable automotive deals. provides multiple car financing options, allowing prospective clients to compare different financing options. In addition, partners with trusted dealerships to give you unbeatable financing options.

So, whether you're looking forward to upgrading your car or looking forward to owning a new car - you can contact us for solutions and advice on car loans and car financing.