Tire Pressure: Everything You Need to Know
You may be surprised by how great of an effect your car’s tire pressure has on your vehicle’s performance.
Jul 10, 2018
Often overlooked and even sometimes forgotten, your car’s tire pressure is an important factor in making sure your car runs optimally. These days, most modern vehicles come equipped with Tire Pressure Monitoring Systems (TPMS), which takes the guesswork out of wondering whether your car’s tire pressure is low or not. But what if your car doesn’t have TPMS? And if it does, are there still things you should know?
You may be surprised by how great of an effect your car’s tire pressure has on your vehicle’s performance. In fact, if you’ve noticed that your gas mileage has gone down a few MPG, it’s likely attributed to your car’s tires.
How do I know if my tires are properly inflated?
Even if your car is equipped with TPMS, you will want to know the recommended tire pressure for your specific vehicle. Typically, there is a sticker found inside the driver’s side door that will list the recommended tire pressure. This figure is normally indicated in PSI, which stands for pounds per square inch of air. In addition, your tire’s maximum air pressure will be labeled on the tire’s sidewall. That figure is the maximum PSI the tire can safely hold. In other words, don’t inflate your tires beyond the number found on the sidewall.
If you are not able to locate a sticker on the inside of your driver’s side door, refer to the owner’s manual to determine the recommended tire pressure for your car.
Keep in mind that the recommended tire pressure values could be different between your front and rear tires. Make sure you’re checking both front and rear values when you’re determining whether your tires are properly inflated.
Why is proper inflation important?
There’s a reason why vehicles have recommended tire pressures. Proper inflation of your car’s tires not only ensures it’s comfortable to drive and ride in, but it can also affect your fuel economy. More importantly, they ensure your tires are wearing out uniformly, extending the life of your tires.
Overinflating or underinflating your tires could have adverse effects on its performance. Not only do underinflated tires appear flatter, they have increased surface contact with the road. If driven over a long period of time, that contact can result in premature tire wear. Underinflation also has a direct effect on the car’s fuel economy.
Overinflating your tires with too much air can cause increased rigidity and stiffness, resulting in a harsher ride. Contact with the road is typically increased around the center area of the tire when it is overinflated, causing additional wear in the center. If you notice the sides or outer sections of your car’s tires are less worn out than the center, it’s a good chance they’re overinflated.
How to check your tire pressure
Checking your car’s tire pressure is a fairly straightforward and simple task. The easiest method is to use a tire pressure gauge that you can purchase online or at any automotive parts store for cheap. It’s normally recommended to check your car’s tire pressure levels when the tires are cold, or after the vehicle has been parked for at least three hours. Since friction causes heat, and heat increases tire pressure, doing a check after driving will likely give you an inaccurate figure. The recommended tire pressures you find in either the decal inside your driver’s side door or in your owner’s manual refers to the tire pressure before you start driving.
Using the tire pressure gauge, remove your valve stem cap and simply place the gauge on the stem with some pressure. A number will appear on the gauge, and it never hurts to check it two or even three times to make sure you have an accurate reading. Once you’ve checked the tire pressure on all four tires, make sure to replace the valve stem cap.
If you don’t own a tire gauge, nearly all public air compressors will have an integrated tire gauge. More modern units at gas stations may have digital readouts to show your tire pressure. If your tire is overinflated, you’ll want to let some air out to get it back to the optimal PSI range. Make sure to check it periodically while you’re letting air out, so you don’t end up underinflating your tires.
Types of air compressors
If you don’t live near a gas station with accessible air, you could invest into a portable air compressor that’s designed to inflate tires. There are, of course, heavy duty air compressors also available. But unless you plan to use it to work on your car, they’re not necessary just for putting air into your tires.
There’s a wide range of offerings when it comes to air compressors and tire inflators, ranging from extremely affordable to fancy digital systems that require a power outlet. There are also 12-volt portable air compressors, which means you can use the cigarette lighter in your car.
If you have access to an air compressor, you can just purchase a tire inflator and gauge, which are also available in digital form. But most car owners won’t have an air compressor in their garage, so you’re likely shopping for a portable air compressor.
When shopping for a portable air compressor, you’ll naturally need to determine your budget and whether the size of the air compressor matters to you. If time is an important factor, some air compressors do inflate tires quicker than others. Keep in mind, with a 12-volt air compressor, you will want to make sure your car’s engine is running while using the air compressor.
Here is a brief overview of some of the most popular air compressors currently available.
AAA Lifeline 300 PSI 12-volt DC Air Compressor
You’ve likely heard of the American Automobiles Association (AAA), but did you know it has its own branded air compressor? The 300 PSI portable tire inflator is capable of inflating a standard spare car tire in eight minutes, thanks to a heavy-duty motor. The compressor’s power cord connects to your car’s cigarette outlet and includes three nozzle adapters for different size inputs.
There’s a built-in pressure gauge on the face of the compressor, letting you know just exactly how much pressure is in your tire. Measuring 12 inches by 10 inches by 8 inches, it’s fairly portable and weighs only 2 pounds. There’s even a mini version that’s even smaller, which is ideal to keep in your car at all times. If you’re willing to spend a bit more, there’s a digital variant also available.
Some users complain of built quality/short life