How do tyres impact fuel consumption?

Rising fuel prices have recently become one of the biggest concerns of drivers. Many car owners wonder what are some of the effective ways to pay less at petrol stations. In this respect, the selection of the right tyres is of considerable importance. This article explains how tyre size affects fuel consumption, and if there’s anything we can do to make the driving experience cheaper.

Fuel expenses can put a huge strain on the household budget.

Impact of tyres on fuel consumption – what does it depend on? 

Many drivers are still unaware of the close link between the tyres and fuel consumption levels. Plenty of factors determine how the right tyres allow us to reduce the fuel bill. Among other things, tyre size, width, tread and wear are the factors that impact it.

The driver’s driving style is also important. In this article, we’ll try to explain all these dependencies. As an introduction, we’d like to encourage you to watch a video in which our expert discusses the basic relations between tyres and fuel consumption.

 

Does tyre size affect petrol mileage?

Tyre width and fuel consumption – how are the two factors related? It’s no secret that the larger the tyre size we opt for, the higher the bill we face at the petrol station. Even a slightly narrower tread can significantly reduce fuel consumption – a difference of 1 centimetre equals a wind resistance reduction (or increase) by an average of 1.5%.

Tyre diameter is also important. The lower the wheel profile, the higher the fuel consumption. The tyre becomes stiffer and the car's grip on the ground increases, which, in turn, increases its rolling resistance while also escalating fuel consumption.

A common practice among drivers is to alter the rim size for aesthetic reasons, which also affects petrol mileage. Changing the size (obviously within the values permitted for the car model in question) can alter tyre stiffness. Choosing a wider tread also increases the contact area between the tyre and the road, which will also be felt in the increased fuel consumption.

Fuel efficiency and rolling resistance – how do they affect petrol consumption?

Before deciding to buy a new set of tyres, let’s familiarise ourselves with the characteristics of the selected model – especially if we want to save money. Since 2021, under a European Union regulation, every manufacturer is obliged to include the relevant data on the label of a specific tyre. It contains key information regarding tyre performance in three key categories:

• fuel efficiency class,
• braking and wet surface grip,
• the level of noise produced.

The lower the rolling resistance, the lower the fuel consumption

If fuel efficiency remains one of the key features while purchasing tyres, we should choose tyre types that stand out for their high energy efficiency. This is because tyre class and fuel consumption are closely linked. Tyres scoring an 'A' will give us the best savings. This is the highest rating on a seven-point scale, guaranteeing low rolling resistance.

Although the difference in fuel consumption of A-class tyres can be as much as 0.5l/100 km compared to E-class tyres, it is important to remember that the choice should not be based on a single parameter. Very often a good score in one category means worse parameters in another one, which can affect the overall driving quality.

Rolling resistance and fuel consumption

Tyre rolling resistance is nothing more than the resistive force applied to the wheel when it's rolling – opposite to the direction of motion. This force slows the vehicle down. The greater the resistance, the more force the car needs to stay in motion. And increased energy intake equals raised fuel consumption.

Rolling resistance is influenced, among other things, by aerodynamic resistance, weight, structure and shape of the tread, microslip and tyre pressure.

Tyre structure matters when it comes to fuel consumption

Tyres, although seemingly similar, differ when it comes to numerous properties. If you are after versions that facilitate economical driving, you should pay attention to, among other things, tyre weight, as this detail definitely affects the level of combustion. The relationship is very simple – the lighter the model, the lower the rolling resistance; hence the car uses less energy to get the wheels rolling.

Tyre tread pattern is key when it comes to reducing fuel consumption

It is one of the factors that has the greatest impact on petrol mileage, contributing to as much as 60% of rolling resistance. The positioning of the blocks, as well as other elements of the tyre crown, influence the deformation or bulging of the tyre during driving, which directly translates into a lower or higher coefficient of rolling friction.

The right compound will reduce fuel consumption levels

Why is it important to check which materials were used to make a particular tyre type? The rubber compound varies greatly depending on the purpose of the tyre. Types with more silica in their composition have lower rolling resistance.

An increasing number of manufacturers are choosing to introduce eco-friendly tyres with compounds developed using more lightweight materials. They usually contain a high content of synthetic rubber. Such rubber composition has the additional effect of lowering rolling resistance, which translates into reducing fuel consumption.

How does tyre wear affect fuel consumption?

In the course of ongoing use, the tyre tread wears down, slowly losing its properties. Surprisingly, as subsequent layers of rubber wear off, the rolling resistance is reduced. However, it is not recommended to even think about such a solution when looking for savings.

Worn tyres have reduced road grip, significantly increase braking distance, and rainy conditions may make the car unsteerable. It is therefore important to replace worn-out tyres with a new set in due time. It is worth remembering to change your tyres before the tread is less than 3 mm deep to keep ourselves and our loved ones safe.

Tyre wear has a great impact on fuel consumption.

Incorrect tyre pressure increases fuel consumption

When thinking about economical driving, don't forget to maintain the correct tyre pressure. It is advisable to drop by a petrol station every four weeks or so and ensure that air pressure stays at the right value; should it drop, correct the difference. Lower pressure means that the tyre bulges and deforms more, resulting in increased rolling resistance.

When it comes to winter, it’s a particularly good idea to check the tyre pressure more frequently, as it can drop by up to 25% when temperatures cool down rapidly. Maintaining the wrong pressure not only increases fuel consumption – it can also have an adverse effect on the condition of the tyres, causing deformation, especially when planning long-term parking.

Economical driving is fundamental to lower fuel consumption

Let's remember that it's not just choosing the right tyres that will help us optimise fuel bills. A driving style that’s far too dynamic won’t yield satisfactory results even with the best premium-class tyres.

When discussing various ways to reduce fuel consumption, it’s worth mentioning eco-driving or the principles of economical driving, which are becoming increasingly popular. With a few simple techniques, drivers can make a significant difference in reducing fuel consumption. All it takes is developing new, good driving habits.

Among several basic methods, we can mention:

• engine braking,
• avoiding dynamic braking and acceleration,
• driving in the highest possible gear,
• controlling the road and our surroundings so that our manoeuvres are planned in advance.