Maximizing Fuel Efficiency With Larger Tires: Strategies For Improvement

Changing to bigger tires can decrease your vehicle's fuel economy due to several factors. Firstly, larger tires are heavier, which increases the overall weight and inertia of the vehicle, requiring more power during acceleration and resulting in higher fuel consumption. Additionally, bigger tires have a greater contact patch with the ground, increasing rolling resistance and requiring more energy to propel the vehicle forward. This increase in rolling resistance, combined with the higher weight, leads to reduced fuel efficiency. Furthermore, the increased size can result in higher wind resistance at higher speeds, requiring more fuel to overcome the force exerted by moving air. While some sources suggest that bigger tires can improve fuel efficiency on freeways due to taller gear ratios, the overall consensus is that upsizing tires will decrease fuel mileage. To optimize fuel efficiency, it is recommended to maintain proper tire pressure, select tires with suitable tread patterns for your driving conditions, and consider narrower tires that offer less wind resistance and rolling resistance.

Check your tyre pressure

Changing to bigger tires can have a significant impact on fuel mileage, and not always for the better. The size of your tires directly influences your vehicle's overall performance and fuel economy.

One of the main ways to increase fuel mileage with bigger tires is to check your tyre pressure. Ensuring your tires are inflated to the correct pressure can improve your gas mileage by 0.6% on average, and up to 3% in some cases. Under-inflated tires can lower gas mileage by about 0.2% for every 1 psi drop in the average pressure of all tires. The correct tire pressure for your vehicle is usually found on a sticker in the driver's side door jamb or the glove box, and in your owner's manual.

Checking your tire pressure is a simple and effective way to ensure your vehicle is operating as efficiently as possible. By maintaining the recommended psi, you can ensure optimum performance. It is recommended that you check your tire pressure regularly, ideally once a month, to ensure your vehicle is running as efficiently as possible.

While checking your tire pressure is a great way to increase fuel mileage, it is important to note that there are other factors to consider when increasing fuel efficiency with bigger tires. For example, larger tires have a higher rolling resistance, which means they require more resistance and effort to get them rolling. Additionally, bigger tires are often heavier, which can also decrease fuel economy as more power is needed to rotate them.

In summary, while bigger tires can offer advantages such as increased traction and a smoother ride, it is important to be mindful of the potential impact on fuel mileage. Regularly checking your tire pressure and ensuring your tires are properly inflated is a simple and effective way to mitigate this impact and improve your vehicle's fuel efficiency.

Opt for narrower tyres

Opting for narrower tyres can be a way to improve fuel mileage after changing to bigger tyres. Narrower tyres have less grip, which results in less resistance to rolling and can lead to improved fuel economy. However, it is important to note that the impact on fuel mileage may be negligible, and it is challenging to quantify the exact gains.

When considering narrower tyres, it is crucial to maintain the overall diameter of the tyre by changing the aspect ratio (the second number in the tyre size). This ensures that the speedometer and odometer remain accurate. Additionally, narrower tyres can result in a loss of handling, ride quality, and stopping power.

It is recommended to consult professionals or refer to the manufacturer's specifications before making tyre size changes, as altering the tyre size can affect braking, handling, load distribution, and even the accuracy of safety features like the speedometer, ABS, and traction control.

Furthermore, the weight of the tyre also plays a role in fuel efficiency. Heavier tyres increase rolling inertia, requiring more power to maintain speed. Therefore, opting for lighter tyres can also contribute to improved fuel mileage.

In summary, while narrower tyres can potentially improve fuel mileage, it is important to consider the trade-offs in terms of handling and ride quality. Additionally, ensuring that the tyres are properly inflated and choosing tyres with low rolling resistance can further contribute to improved fuel economy.

Reduce vehicle weight

Changing to bigger tires can reduce your fuel mileage due to the increased weight and rotational mass, which requires more energy to accelerate and maintain speed. To compensate for this and improve fuel efficiency, one strategy is to reduce the overall weight of your vehicle. Here are some ways to do that:

Reduce Weight in the Trunk/Boot

Clear out any unnecessary items from your trunk or boot. Every extra 50 kg or 100 pounds of weight in your car increases fuel consumption by 2% to 4%. The reduction is relative to the vehicle's weight, so smaller vehicles are more affected by increased weight than larger ones. If you're carrying extra weight, you may be spending up to four cents more per gallon of fuel.

Remove Roof Racks and Boxes

If you have roof racks or boxes that are not in use, consider removing them. These add weight and increase wind resistance, both of which negatively impact fuel efficiency. Streamlining your vehicle's profile can help it cut through the air more efficiently, reducing drag and improving mileage.

Opt for Lighter Wheels

When choosing bigger tires, consider selecting wheels that are relatively lighter in weight. This can help offset the additional mass of the larger tires, reducing the overall weight of your rotating assembly. Lighter wheels may also improve handling and acceleration.

Lose Weight Inside the Cabin

Just as with the trunk, remove any unnecessary items from the cabin of your vehicle. This includes removing heavy floor mats, spare change, and any other items that add weight. If you have aftermarket seats that are heavier than stock, consider swapping them out for lighter alternatives.

Lose Weight Under the Hood

Look for opportunities to reduce weight under the hood. This could include removing heavy aftermarket components, such as large intake and exhaust systems, or opting for lightweight alternatives for certain parts. However, always consult a mechanic or a specialist before removing or replacing any engine components to ensure you don't compromise the vehicle's performance or safety.

Improve aerodynamics

Improving the aerodynamics of your vehicle is an important step in increasing fuel mileage. Here are some ways to do that:

Rounded Edges at the Front of the Vehicle

Sharp corners and edges increase turbulence and drag, so having smooth and rounded edges at the front of your vehicle will help reduce it. This is because aerodynamics is the study of airflow around your car, and the smoother the airflow, the lower the drag and the less fuel you burn at a specific speed.

Optimise Grill Openings

Grill openings can be optimised to reduce turbulence both outside the car and under the hood. Some car makers have even experimented with adjustable grill slats to fine-tune the airflow.

Install Spats or Spoilers in Front of the Tyres

Spats, or small spoilers, can be installed in front of the tyres to reduce turbulence. This is because turbulence and pressure differences contribute to aerodynamic drag.

Shape the Outside Mirrors and Mounts Carefully

Outside mirrors and their mounts should be carefully shaped to improve aerodynamics. This is because 'skin friction' as air passes over a surface is a real phenomenon and contributes to drag.

Aerodynamically Optimise Water Channels on A-Pillars

Even the water channels on A-pillars can be optimised for aerodynamics.

Adjust the Front Fascia and Air Dam to Reduce Drag Under the Vehicle

Adjusting the front fascia and air dam can help to reduce drag under the vehicle.

Install a Rear Spoiler

A rear spoiler can help to reduce lift and improve aerodynamics.

Adjust the Angle of the Rear Window

Carefully calculating the angle of the rear window can improve aerodynamics.

Install a Diffuser to Tune Air Coming off the Underside

A rear diffuser can be used to tune and control the air coming off the underside of the vehicle.

Install Belly Pans to Smooth Airflow Under the Vehicle

Belly pans, or underbody panels, can be installed to cover components and smooth airflow under the vehicle.

Remove Roof Racks

Roof racks have a negative impact on aerodynamics, so removing them will help to improve airflow.

Roll Up Your Windows

Rolling up your windows, particularly at highway speeds, will improve aerodynamics. An open window creates an entry point for airflow, increasing drag.

Choose Narrower Tyres

Wider tyres increase aerodynamic drag, so choosing narrower alternatives can help to improve aerodynamics and fuel mileage.

Use a different tyre compound

When it comes to improving fuel mileage after switching to bigger tyres, one strategy to consider is using a different tyre compound. Tyre compounds play a crucial role in determining fuel efficiency, and selecting the right compound can help mitigate the negative impact of larger tyres on fuel economy.

Firstly, it's important to understand that tyre compounds are made from a mixture of rubber and other materials, such as carbon black, silica, and oils. The specific combination of these materials determines the characteristics of the compound, including its hardness, flexibility, and rolling resistance. Rolling resistance, also known as tyre friction, is a critical factor in fuel efficiency. Tyres with higher rolling resistance require more energy to turn, which increases fuel consumption.

When choosing a tyre compound, look for options that offer a balance between grip and rolling resistance. Softer compounds tend to provide better grip and are often used in performance tyres, but they may also increase rolling resistance and fuel consumption. Harder compounds, on the other hand, typically offer lower rolling resistance and improved fuel efficiency but may compromise on grip.

Additionally, consider the type of driving you do most often. If you frequently drive on highways, a harder compound may be more suitable as it can provide better fuel efficiency at higher speeds. On the other hand, if you mostly drive in the city, a softer compound may be preferable as it can offer better grip and traction in stop-and-go traffic.

It's worth noting that tyre compounds are not a one-size-fits-all solution. The optimal compound for your vehicle will depend on various factors, including driving conditions, climate, and your own driving style. It's always a good idea to consult a tyre expert or a mechanic who can provide personalised recommendations based on your specific needs and vehicle specifications.

Furthermore, keep in mind that tyre compounds are just one piece of the puzzle when it comes to improving fuel mileage. Other factors, such as tyre size, wheel specifications, vehicle weight, and driving habits, also play a significant role in fuel efficiency. By combining the right tyre compound with other fuel-saving strategies, you can maximise your fuel economy, even with bigger tyres.

Frequently asked questions