Use Low Rolling Resistance Tires for the Best Gas Mileage

Low rolling resistance tires have been around for a while. Are they worth the hype? Excess pressure accumulation along the tires can greatly dip into your gas budget.

So, better be prepared and know what you are getting into. In this post, we will explain and go through everything you need to know about low rolling resistance tires and what to look for to keep fuel costs reduced.

What Is Tire Rolling Resistance?

The tire rolling resistance is the pressure generated when the tires are in motion. It is created by the accelerating and braking friction affecting the footprint and the vehicle's weight placed on the tire.

Higher rolling resistance tires are responsible for about 4-7% of the vehicle's energy usage, as well as 4% of the CO2 emissions in the world. This data is provided by Michelin, who works on manufacturing high mileage tires to combat this issue.

When tires are in use, their contact patch is constantly shifting and forming when it connects with the road. However, this deformation is necessary to generate a grip the vehicle can use for its performance. During this process, higher energy levels are necessary. But, reducing this friction helps to increase gas mileage.

What Is Gas Mileage?

Gas mileage, or mpg for short, represents the miles a vehicle can travel using one gallon of fuel. It basically shows how much fuel a vehicle needs to function, and each vehicle's mpg is classified by the Environmental Protection Agency (EPA).

Many different factors contribute to determining the mpg of a car. Road conditions and the density of traffic affect fuel efficiency significantly. Due to this, there are three mpg categories determined by the EPA. They are:

• City mpg: The vehicle's average rating in urban areas where traffic jams and traffic stops influence fuel usage.
• Highway mpg: The vehicle's average rating on highways and long stretch roads, where stops are less frequent.
• Combined mpg: The combination of the average highway and city mpg ratings of the vehicle.

One good way to improve your gas mileage is to maintain a proper car and tire maintenance routine.

What Are Fuel Efficient Tires?

Technically, no definition specifies what a fuel-efficient tire is. This is because currently, no industry regulations exist that determine one fuel economy tire from the other.

However, with tire technology advancements, tire manufacturers work to outcompete one another and sell more of their products. Additional specifications, such as the MPG fuel efficiency stickers, help with this process.

What Are LRR Tires and Why Are They Important?

Low rolling resistant tires strive to provide decreased gas mileage by reducing the energy usage at the area where the tire tread meets the road and deforms. An energy-efficient tire set is able to minimize deformation, lessening the rolling resistance.

Due to this, along with rising fuel prices and stricter environmental restrictions, the popularity of economy tires is steadily rising. This is causing tire manufacturers to focus on optimizing tire technology in order to design original equipment tires that improve fuel economy, even for electric vehicles.

Low Rolling Resistance Technology

While their technologies may differ, fuel-saver tires have one thing in common. All of them are designed and optimized to generate low rolling resistance throughout their performance. Tire brands manage to achieve this in multiple ways.

Tread Compound Blend

Advancements in tire technology have allowed manufacturers to create heat-resistant rubber compound blends. Fuel-saving tires are made using these harder compounds that help decrease pressure accumulation, and thus rolling resistance. In other words, the higher the tread wear rating of a tire, the better its fuel economy is.

Sidewall Stiffness

Stiffer sidewalls decrease the deformation process while the tires are in motion. As long as the sidewall keeps its ideal shape, it is able to handle the pressure and vehicle weight placed on it better. This is crucial because the pressure of your tires can affect your gas mileage greatly.

Tread Design

Does tire tread affect gas mileage? To put it simply: yes, it does.

The reason for poor gas mileage might be a bulky tire design. When tread elements have room to wiggle around, they increase fuel usage by generating more rolling resistance. To combat this, tire brands design models with continuous tread elements and narrow tread depth. This greatly decreases tread flexing, as the tread elements roll as one unit.

Footprint Width

The smaller a tire's contact patch to more fuel-efficient it is. Hybrid and electric vehicles sport narrower tires for this reason. The average width of a tire is between 185 and 235 mm, which will offer improved fuel efficiency compared to wide tires. The best tire size for fuel economy does not really exist, but bigger tires and gas mileage don't go hand in hand.

Tire Weight

The weight of the car's tires, brakes, wheels, and suspension system also influences fuel economy. The vehicle's heavier unsprung weight results in bad gas mileage. Therefore, brands have been working on reducing the overall tire weight to help fix this issue.

Are Low Rolling Resistance Tires Worth It?

Can tires affect gas mileage in a significant manner? The answer might not be that straightforward.

While it is hard to say a specific dollar amount that you will save, using economic tires will help in increasing mileage and fuel economy. The problem is that there is no overarching fuel efficiency test tire manufacturers can use.

Instead, they compare their new tire designs to older ones to determine their fuel economy in controlled environments. However, as other factors also contribute to the decrease in rolling resistance, on-road results may vary.

Still, low rolling resistance tires definitely increase fuel economy and are worth a try.

Why Does Gas Mileage Drop with New Tires?

New tires are not the best when it comes to rolling resistance. Even if tire specifications state that they are low rolling resistance models, the excessive traction and hydroplaning resistance they provide will increase friction.

When switching to new tires, the tread elements generate traction and snow grip and the grooves prevent hydroplaning. But, at the same time, this stronger traction creates more pressure that enhances the rolling resistance. Still, don't worry, as soon as the tread wears out a bit, the fuel economy will become significantly better.

How Do Tire Treads Increase Friction?

Optimal tire tread also improves fuel economy. Tires generate most of their rolling resistance with their tread patterns. This is because the tread elements deform when they come into contact with the driving surface. When tires feature bulky, individual tread elements and deeper tread depths, this deformation is more prominent.

Unfortunately, tread patterns are needed as they ensure driving safety. To combat the problem, tire brands try to use pressure build-up resistant compounds to mold tires that feature shallower depths and continuous, ribbed tread designs. This helps minimize the possibility of pressure accumulation as tread flexing is greatly reduced.

Of course, we all wish to purchase the best tires for the lowest amount possible. Still, looking for tires that provide longer usability and lower rolling resistance will help us safe in the long run. The tread depth left on the tires also affects its energy efficiency. The lower the tread, the less rolling resistance will accumulate, but driving on worn-out is also not ideal.

How to Measure Tread Depth?

You can improve your gas mileage by purchasing tires with optimized tread patterns. Yet, the footprint wears with use and it is crucial to know when tires should not be used anymore. Therefore, knowing how to measure tread depth is a must for every car owner.

There are different ways you can go about measuring your tire's tread depth:

• By using a tread gauge
• The penny test
• Using a ruler

For more information about tread depth measurements, check our Tread Depth Made Easy blog.

Fuel Economy Only Works With Properly Inflated Tires

Keeping your tires properly inflated will improve your vehicle's fuel efficiency. The improper inflation of a tire is one of the causes of bad gas mileage. It quickly leads to numerous undesirable outcomes, not just high rolling resistance levels. Additionally, an underinflated tire is just as bad as too much tire pressure.

Tires should be inflated at the upper level of the recommended range for best fuel efficiency. The recommended tire air pressure can typically be found on the tire's sidewall or in the vehicle's owner's manual.

Driving with low tire pressure will significantly increase rolling resistance, as the vehicle will consume more energy keeping the tires in motion. Furthermore, a low psi tire will develop irregular tread wear along its tread area, as the shoulders will wear quickly compared to the rest of the footprint. In extreme cases, a blowout can happen if a tire is underinflated.

Psi levels that are above the average car tire pressure result in overinflated tires. This is also an issue, While it can help reduce the rolling resistance, it damages the tire's internal structure and shortens its service life.

So, how do tires affect gas mileage in this manner? Both driving on low tire pressure and using overinflated tires will result in tire damage and increased fuel consumption in the long run.

How Does Low Tire Pressure Affect Gas Mileage?

It goes without saying that properly inflated tires help increase gas mileage. For this reason, tire pressure and gas mileage have a strong correlation. The best tire pressure for gas mileage is the one recommended by the tire manufacturer and it is different for each tire size.

To find the best tire pressure for mpg, check the sidewall of your tires. You will see "Max. Press" followed by numbers. Look for the psi marking and the keep psi a bit lower than the tire's maximum. Usually, for P-rated tires, around 40-44 psi is ideal for a fuel-efficient drive. This will allow your tires to run smoothly in a fuel-efficient manner. Please make sure your tires can handle that psi level before filling them up.

Does Tire Size Affect Gas Mileage?

Yes, tire size is a major factor that decreases or improves fuel economy. The tire rolling radius and the footprint width both need extra energy to maintain motion, but a smaller tire turns more times. So, are smaller or larger diameter tires better for gas mileage?

Big Tires vs Small Tires

When strictly looking at the fuel economy of tires, size matters. Bigger tires are heavier, even when we are looking at low profile tires. Their construction is more durable, but the extra reinforcement makes the tire significantly heavier.

Compared to this, smaller tires are lighter, which lowers their rolling resistance. So, that means that smaller tires are better? Not exactly. While it is easier to get them moving, the vehicle will have to work harder to keep that motion.

This is because smaller tires take longer to cover the same distance as larger tires. In the end, weight and size both contribute to tire size fuel economy calculations.

Wider vs Narrow Tires

Basically, the smaller a tire's contact patch, the better fuel efficiency it will offer. Wider tires feature a larger footprint that creates more friction - aka rolling resistance - during the drive. Compared to this, narrow footprints generate less friction, resulting in a fuel-conscious drive.

The average tire size range for fuel efficiency is between 185 and 235 mm for the footprint width.

Do Wider Tires Use More Gas?

Yes, wider tires use more gas. This is due to their ability to handle sharp handling while offering better traction. Sadly this combination places more pressure on the footprint and increases the rolling resistance. However, the debate about wider vs narrow tires does not end there, as they offer many other positive characteristics - fuel economy is just not among them.

Does Nitrogen in Tires Make a Difference?

Another important debate when it comes to fuel efficiency is "nitrogen versus air in tires".

As maintaining proper tire pressure levels is crucial for fuel economy, nitrogen tires might be the better choice. Nitrogen-filled tires are able to reduce pressure loss, especially when temperatures change. Compared to this, air-filled tires can easily fall victim to low pressure levels when temperatures suddenly change or when the tires heat up.

Nitrogen tires offer other beneficial aspects as well, but, unlike air-filled tires, drivers need to pay to have their refilled. If you are thinking about the benefits of nitrogen in tires and need more help deciding, take a moment to read our blog post about the topic.