Tyre Pressure and Tread: The Big Impact It Has On Your Fuel Economy

Whether it’s your fleet or personal vehicle, tyre pressure and tread play a silent but massive role in fuel economy, which is directly linked to fuel consumption and, as a result, fuel costs. 

Tyre pressure is often overlooked—that is, until you are lost and stuck in the middle of nowhere, wondering why your fleet or car used a ridiculous amount of fuel over a relatively short distance, not realising that it may have something to do with your tyre pressure, your tread, or both.

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In this article, you will:

• Explore the definitions of fuel economy, tyre pressure and tread

• Discover why South Africans should be concerned about fuel economy

• Understand the effects of overinflated and underinflated tyres on fuel economy

• Find out the impact of tyre tread and pressure on fuel economy

• Learn how to skyrocket your fuel economy with Cartrack’s innovative solutions

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Navigating fuel economy, tyre pressure and tread 

According to Forbes, tyre tread contributes to almost a third of a vehicle’s fuel economy.

Learn to save on fuel costs by educating yourself on fuel economy, tyre pressure, and tread below:  

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Navigating fuel economy 

• Defining fuel economy: Fuel economy is the distance a vehicle can reach while running on a fixed amount of fuel. You calculate it by dividing the distance you travelled in kilometres by the number of litres in the vehicle. In other words, kilometres per litre (km/l). Many descriptions of this concept rely on the USA’s metric, which translates to mpg or miles per gallon. 
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• Exploring the calculation: The calculation can become more complex. The distance your vehicle or fleet may be able to travel can be influenced by a lot of factors, including: 
  • Car size 
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  • Style of driving
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  • Cruise control usage
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  • Cargo weight
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  • Terrain

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The difference between fuel economy and fuel efficiency 

It is essential to define fuel efficiency, as many assume fuel efficiency and fuel economy are the same thing.

Fuel economy is specific to distance, and while fuel efficiency is calculated the same way, this concept is simply used to describe how to use fuel, in general, to ensure that as little as possible is used.   

Lori Baker’s article for MIT School Of Engineering, “What’s the difference between fuel efficiency and fuel economy” clarifies this difference by explaining that fuel economy means miles per gallon. On the other hand, fuel efficiency is instead used to describe how efficiently fuel is used.  

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Navigating tyre pressure and tread

• Defining tyre pressure: Tyre pressure is the volume of air pumped into a tyre. It helps stabilise vehicles by ensuring that each tyre has the correct pressure. 
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• Defining tyre tread: Tyre treads are the grooves or patterns on tyre exteriors. These treads are designed to ensure vehicles have a solid grip on the road's surface.

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Why everyday South Africans and businesses should pay attention to fuel economy

Petrol prices have caused everyday South Africans and businesses’ fleet management departments to reach much too deep into their pockets, calling for innovative ways to handle fuel consumption. Riding off the Volvo numbers above, it is clear that improving fuel economy is an effective way to reduce fuel costs, whether you are a fleet manager or an everyday car owner.

Find out more about the cost benefits and other advantages of improving your fuel economy below: 

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Cost benefits expanded

• Fuel costs: As mentioned, improving your fuel economy will reduce fuel costs, as less fuel will be used over certain distances. This also means you can budget to drive longer distances with the same amount of fuel you were using before you improved your fuel economy.
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• Maintenance costs: If you travel the same distance with less fuel, there will likely be less wear and tear. This wearing away prevents engine maintenance and the associated costs, as well as unnecessary downtime.
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• Geographical expansion: Regarding business, if fleet managers choose to use the extra fuel that would have been used at a previously outlined distance, fleet delivery could be geographically expanded to reach a broader customer base. This expansion means fleet managers can obtain more clients and sell more products, improving business expansion overall.
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• Net profit and disposable income: Fleet controllers can also simply increase their net profit, and individuals could use the extra money to pay for basic resources or generate disposable income. 

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Making and saving money while saving the environment

Less fuel consumption means less smoke will be released from the exhaust—this smoke contains harmful gases that negatively impact the environment, such as carbon dioxide, nitrogen oxide and carbon monoxide. 

Beyond the positive environmental impact, this can lead to good standing with current or new customers, partners, or other businesses. 

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Increasing fleet productivity 

Using less fuel over a certain distance allows fleet drivers to stop less often to refuel. Fewer stops save time, make deliveries more efficient and improve fleet productivity. 

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Tyre pressure and tread and its impact on fuel economy  

Tyre pressure impacts many parts of your driving experience, from smooth rides to flat tyres. It impacts the safety of the driver and all the passengers or goods in the vehicle. Overall, vehicle performance worsens if tyres are overinflated or underinflated, and high fuel economy is just one of the negative consequences.

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Increased Fuel Use 

Increased fuel consumption means that a vehicle will travel less distance than it could have if there had been less fuel consumption, directly influencing fuel economy. Both overinflated and underinflated tyres can lead to a climb in fuel consumption.

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Underinflated tyres 

•  Expanding the tyre's contact with the road increases rolling resistance, boosting fuel consumption as the engine works harder. According to Forbes, “Rolling resistance accounts for around 9% of a truck’s fuel consumption.”
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•  Impact on fleet management: Three researchers applied this fact to fleets in a 2019 journal article that investigated the influence of tyre pressure on fuel consumption in trucks.  According to their research, tyre pressure is a core factor affecting vehicle efficiency, rolling resistance and fuel consumption.
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• Tyre bending: Lower tyre pressure will also increase rolling resistance, leading to tyre bending. 

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Overinflated tyres 

There is a misconception that overinflated tyres can improve fuel economy. While this can be true to a slight extent, the more overinflated the tyre and the longer the overinflation continues, the more opposing results can occur. The relationship between overinflated tyres and fuel consumption is more complex.

The graph below shows the assumption that fuel consumption falls with more inflation. As the tyre inflates to 3.0 bars of tyre pressure (represented by the red line), fuel consumption decreases to 10.9 at 1/100 or 1 litre per kilometre (represented by the blue line). These numbers are all accurate, but there is more to it. 

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While tyre overinflation may not be directly related to elevated fuel consumption, it causes wear and tear over time, which increases rolling resistance. This results in a rise in fuel consumption, bringing about a swell in fuel economy.

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Tyre tread and its impact on fuel economy

Tyre tread and patterns also affect fuel economy, sometimes overlapping with tyre pressure. For example, when overinflated tyres wear and tear, the tyre tread wears out, especially in the centre, and so, once again, rolling resistance climbs.

Discover more about tyre tread, patterns and their relation to fuel economy: 

• Increased tyre grip: The greater the tread depth, the more grip the vehicle has, leading to better fuel economy and vice versa. This fuel economy boost is because the car won’t need as much fuel for movement.
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• Deforming tyres: Tread patterns, which help vehicle traction, significantly influence fuel consumption, either negatively or positively, based on the vehicle type and context of where and what condition the vehicle or fleet is driving in. Some of these examples include:
  • ‍Rib patterns: Rib patterns are overwhelmingly recommended because they have lower resistance and are parallel to the tyres on the road.
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  • ‍Standard energy tyres: Standard energy tyres are not recommended for low fuel economy in private vehicles, as their patterns are not designed to improve fuel efficiency but create more rolling resistance. However, these tyres are still used in most vehicles. According to a Tyre World Medium article, they are manufactured for the general population to provide durability and comfort.
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  •  Aggressive tread patterns: It is not recommended to employ aggressive tread patterns on highways, as they can heighten rolling resistance. These tread patterns are constructed for off-road use. 

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Skyrocket your fuel economy with Cartrack’s innovative solutions

Cartrack’s innovative solutions will help you prevent and detect a possible increase in fuel economy. Explore more below:

• Automated Preventative Maintenance: With our automated preventative maintenance solution, fleet managers can easily track any maintenance needs and tend to them before they become a more significant, more expensive, and time-consuming issue, with more in-depth fixes and longer downtime. These solutions include real-time alerts so you can know precisely when it's time to put more air in or replace tyres, making sure that there is no delay in ensuring that your fuel economy is at a healthy level.
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• Fuel Monitoring: Cartrack’s fuel consumption monitoring can help you track your fleet's fuel usage and note any spikes in usage. While this does not necessarily mean that the tyres are the issue, it can point to other problems affecting your fuel economy, including your tyres, and so can help you address them ahead of time.
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• Driver behaviour: Using our driver behaviour solutions, such as driver scorecards and driver behaviour reports, fleet managers can monitor whether drivers engage in behaviours that potentially damage their tyres.
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• Driver scorecards: Driver scorecards allow you to observe your drivers for harsh behaviours and reward them with high ratings if they behave well. Some of these harsh behaviours, such as speeding or harsh acceleration, can damage tyres. In other words, incentivising drivers to drive safely, whether through high ratings or motivating them through other means, such as bonuses or raises, can help you avoid damaging your fleet’s tyres and negatively impacting your fuel economy. 
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• Driver behaviour reports: Driver behaviour reports provide in-depth insight into your driver’s habits, such as keeping track of all harsh behaviours for every driver over time. Once again, this can help you spot behaviours damaging your fleets’ tyres. You can also request instant trip reports to help combat harsh behaviours in real time. 
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• Car tyre deals: If you are not running a fleet and are looking to improve your fuel economy as a personal-use driver, Cartrack experts can negotiate car tyre deals for you, ensuring you get prime tyres for fuel economy. 

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Answering your all-consuming fuel economy questions (FAQs)

Q: How do tyres reduce fuel consumption? 

A: As mentioned, tread patterns can reduce fuel consumption depending on various factors, such as tyre pressure, whether the pressure is set correctly, and whether it is over- or underinflated. 

In addition, wheel alignment, size, and weight can reduce fuel consumption, among many other factors.

Wheel alignment can reduce or increase fuel consumption depending on whether they’re misaligned. Misaligned wheels drag, so they use more fuel, requiring the engine to work harder. 

Adequately aligned wheels, however, have the opposite effect. There won’t be as much drag, the engine will be less stressed, and fuel consumption will be lower. 

Tyre weight affects rolling resistance in that the lighter the tyre, the less rolling resistance there is, and vice versa, decreasing and increasing fuel consumption subsequently. 

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Q: What is the best tyre pressure?

A: Tyre pressure is measured in bars or PSI (pounds per square inch). While every vehicle has required tyre pressure, the generally recommended and accepted pressure measurement is between 28 and 36 PSI, which converts to approximately 1.9 to 2.5 bars. 

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Q: How can I choose the right tyres for better fuel economy?

A: Investing in energy-efficient tyres, also known as “eco-tyres” or “green tyres,” is one great way to choose the right tyres for better fuel economy. These tyres are low-resistant. While they may be high-priced, the costs you will save in the long run will outweigh the initial expenses. 

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Q: How can I improve my fuel economy?

A: There are many ways you can improve fuel economy, including ensuring that your tyre pressure is at the correct PSI or bar and getting them pumped when necessary is one way to do so. Another is looking after and choosing the right tyres and ensuring your wheel alignment is in order.

Regular maintenance and no speeding, rapid acceleration, or coasting are also recommended. Try to maintain a consistent speed or move into cruise control when suitable. Remove any extra weight or unnecessary cargo from your vehicle or fleet. 

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Get a grip on your fleet by investing in Cartrack's fleet management solutions

At Cartrack Zimbabwe, we aim to simplify and automate your fleet management experience with various solutions such as real-time tracking, increasing delivery efficiency and route optimisation. 

Contact us today to increase your fleet’s grip on the road and your profits.