Most people don't bother regularly checking their tire pressures, but some would argue that tire pressure is just as important as making sure you have enough oil and coolant in the engine. Overinflated or underinflated tires have a severe impact on how your car drives and behaves, as well as your gas mileage and tire life.

Thankfully, adjusting your tire pressures and getting them to where they need to be is relatively easy provided you know what your tire pressure values are, how to measure your tire pressure, and how to inflate or deflate them as needed. This article will go over everything you need to know to get your tires where they need to be.

Understanding Tire Pressure and its Importance for Safe Driving

Tire pressure represents how much air is inside your car's tire. As you inflate your tire with air, the pressure inside the tire itself increases since there's a limited amount of space, and the air is forced to compress to fit inside. Vice versa, as you deflate your tire and air escapes, the pressure inside is relieved.

The tire needs air to work and function as intended. A completely flat tire means that the wheel – the rim itself – is sitting on the pavement with only a thin layer of rubber insulating it from the road. It crushes the rubber and ruins the sidewall. That's why it's not recommended to drive with a flat or nearly flat tire since the risk of damaging the rim and tire is extremely high. Air provides a cushion between the rim and the tire, meaning that only the tire makes contact with the road, and not the rim.

Underinflation issues

If you have a tire that is underinflated, not only are you risking damaging the rim, but you're a potential safety hazard to yourself and everyone else in traffic. Since the tire doesn't have enough air to keep itself completely upright, a larger portion of the tire surface makes contact with the road which increases friction. This means that your tire will wear out much quicker than normal, not to mention that it can also lead to overheating issues that can subsequently cause catastrophic tire failure such as tread separation and blowouts.

Running extremely low tire pressures is only recommended in low-grip situations such as when driving in mud, snow, or sand, but those scenarios are typically reserved for off-roading. For just general driving on public roads, you want to have your tires inflated to the manufacturer's recommended values.

Overinflation issues

Likewise, if you have an overinflated tire meaning that the pressure inside is higher than recommended by the manufacturer, the center of the tire tread will wear out much quicker since that's the part that tends to bulge out when the tire is overinflated. Overinflated tires are also much more prone to blowouts since the tire is under enormous stress from internal pressure. Hitting a pothole or a curb, especially at speed, might cause the tire to blow out and cause you to lose control of your vehicle.

If you drive a car with underinflated tires, the first thing you'll notice is just how abrupt and sharp every bump feels. Since there's not enough air in the tires to absorb the shocks and vibrations, you'll feel more of them in the cabin through the wheels and the suspension. As you can imagine, this also isn't great for wheel and suspension components' longevity. Underinflated tires can also increase fuel consumption by as much as 10% and reduce tire life by as much as 25%.

Overinflated tires will cause a stiff ride, making even the most minute of road imperfections be completely felt through the steering wheel. Since the air pressure inside the tires is too high, the margin the tires have for absorbing shocks and impacts is significantly lower than usual. The tire is unable to deform and absorb road imperfections since the air is pressing inside the tire walls, making the tire incredibly stiff.

A report from the Road Safety Authority found that defective tires were to blame in two-thirds of all fatal car crashes. Since tires are the only point of contact between your car and the pavement underneath, it's important that they're in good shape with plenty of tread, but it's just as important that they're set at the correct tire pressure.

Where to Find the Specific Tire Pressure for Your Vehicle

If you have a newer car built in the last 20 to 30 years, you can usually find the recommended tire pressure listed on a sticker placed inside the driver's door on the pillar or door edge itself. If your car doesn't have this sticker, you can almost always find the recommended tire pressure inside the owner's manual.

If for some reason you can't find the owner's manual, you can typically find the specific tire pressure for your vehicle's make and manufacturer online, either on a forum dedicated for your car or on a website listing online owner's manuals.

Most manufacturers will recommend tire pressures anywhere between 32 psi to 35 psi, but every car is different so you always have to check what the manufacturer recommends for your specific model. A large 4x4 will obviously require different tire pressures than a small hatchback with wheels half the size.

Tools You Should Have to Help Manage Your Tire Pressure

A simple tire pressure gauge is typically all you need to measure tire pressure. If you have an air compressor, whether it's a fixed or a mobile one designed to be carried inside the car, you don't have to worry about purchasing a separate tire pressure gauge since compressors usually come with a built-in one.

Just remember that you should check tire pressure when the tires are cold and the car hasn't been driven for the most accurate reading. Heat will typically cause the temperature and the air pressure inside the tires to rise, which can cause incorrect tire pressure readings.

Last but not least, it's important to note that the tire pressure listed on the side of the tire is the maximum tire pressure the tire can take without exploding, not the recommended tire pressure. As we said previously, the recommended tire pressure can be found on the sticker placed inside the driver's side door or the owner's manual.