Why Should Tire Pressure Be Higher When Driving At High Speeds?

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It is often said on the street that it is better to use higher tire pressure on the highway. But what are the actual benefits and what mechanism is responsible for these benefits?

There are many different opinions, and many people may be confused. In this article, we will explain why higher tire pressure is recommended for high-speed driving.

What Happens When Air Pressure Is Low?

To begin with, the proper air pressure is specified as the basic premise. This is largely related to the size and weight of the vehicle and is specified depending on the type of vehicle. Let’s check the following points to see what will happen if you drive with a lower air pressure than the correct air pressure for your tires.

Decreased Fuel Economy

The fuel economy tends to deteriorate when tires are underinflated. This is because under-inflation of tires causes the rubber itself to deflect, making it impossible to maintain proper body posture and increasing the rolling resistance of the tires, which has a negative effect on fuel economy.

Maintaining proper tire inflation pressure will help to prevent the decline in fuel economy.

Decreased Tire Life

When tires are underinflated below the proper pressure, it tends to shorten the life of the tire itself. This also means that the tires will not maintain their original shape, which increases rolling resistance and friction, damaging the tires.

Instead of evenly worn tire crests, uneven wear reduces the life of the tire more. Uneven wear also increases the risk of tire bursts and punctures.

Ride Quality Will Deteriorate

Ride quality tends to deteriorate when tires are underinflated. Tires have the ability to absorb road surface irregularities, and when tires are underinflated below the specified pressure, they fail to do their job and transmit fine vibrations to passengers.

Extremely low air pressure can also damage the wheels when going over bumps.

What Is The Air Pressure On A (Typical) Street?

As mentioned above, tires have a proper air pressure, which is specified for each type of vehicle and should be adjusted to the correct pressure for your vehicle. Usually, there is a sticker on the driver’s door of the car that says “Specified Air Pressure”. Or it is clearly indicated in the owner’s manual.

Generally, the correct air pressure is indicated in “kgf/cm2”. Depending on the type of car, units such as “kPa (kilopascal),” “bar (bar),” or “PSI (PSI)” may be used, but for domestic cars, “kgf/cm2” is the first indication clearly stated.

In addition, some car models have detailed designated air pressure depending on the load weight and the number of passengers.

What Is The Recommended Air Pressure For Highway Driving?

Until a decade ago, bias tires were installed at a high rate, and there were concerns about tire deformation and bursting at high speeds when tires were under the proper inflation pressure. Today, with the spread and evolution of radial tires, the performance of the tires themselves has improved and tire deformation has been minimized.

However, there is still a difference in the burden placed on tires when driving on ordinary roads and on highways. When driving at high speeds, there is no particular need to increase tire pressure, but it is important to ensure that the tires are maintained at the specified pressure.

Pre-inflation pressure checks are essential for safety reasons, such as tire deformation due to centrifugal force, uneven wear, or reduced grip due to heat sag.

The common recommendation to increase air pressure by 10% at high speeds is a safety measure to maintain minimum specified air pressure as a margin against the air that is naturally released little by little every day and is not a special recommendation by tire or car manufacturers.

It is not something that is specifically specified by the tire manufacturer or car manufacturer. This is a remnant of the “specified air pressure” for high-speed driving that was specified for cars not so long ago. It is said that most tire burst accidents on highways are caused by inadequate inspections.

Even if nothing is done, the air pressure is decreasing day by day, and checking the tire pressure once a month is recommended. Knowing the proper tire pressure and maintaining proper tire pressure will help ensure safe and economical driving.

It is recommended that you visit a gas station or tire store on a regular basis to check and manage your tires along with any flaws.