Hey there, I’m Robby – your friendly certified master mechanic with over 20 years of experience under the hood. If there’s one thing I’ve learned after countless oil changes and tire rotations, it’s that properly inflated tires are crucial for safe handling, maximum tread life, and saving money at the pump. Driving on under or over-inflated tires can be downright dangerous.
That’s why I put together this comprehensive guide on checking and adjusting tire pressure. Inside, I’ll walk you through how and when to accurately check your PSI, what to watch out for, and how to inflate or deflate your tires to the right level. You’ll also learn how temperature impacts readings and the consequences of improper inflation.
Consider me your expert guide on How To Check Tire Pressure and maintaining perfect tire pressure. With just a pressure gauge and a few minutes each month, you can optimize your vehicle’s ride, handling, tire wear, and fuel economy. Let’s get you rolling on the right PSI!
How To Check Tire Pressure – Quick Steps
|1||Determine recommended PSI from door jamb sticker or owner’s manual|
|2||Check pressure when tires are cold after sitting 3+ hours|
|3||Remove valve caps and set aside|
|4||Check pressure on each tire with an accurate gauge|
|5||Check remaining tires using the same process|
|6||Inflate any under-inflated tires to reach the recommended PSI|
|7||Deflate over-inflated tires by depressing valve stem briefly|
|8||Recheck pressure on any tires you adjusted|
|9||Replace valve caps on all four tires|
|10||Retest inflation monthly|
The Importance of Proper Tire Inflation
The rubber meets the road through your tires, making them a critical component for safe handling and smooth rides. Under-inflated tires can lead to blowouts, reduced control, longer stopping distances, and uneven wear. Over-inflated tires may actually wear faster in the center and could hydroplane easier. Monitoring and maintaining pressure within the vehicle manufacturer’s recommended range keeps your tires in their prime.
How Often Should Tire Pressure Be Checked?
To stay on top of proper inflation, you should check all tires including the spare at least once per month. I recommend checking pressure every time you fill up on gas. Get in the habit of using the same pressure gauge each time for consistency.
Always check tires when they are “cold” – meaning parked for 3+ hours and driven less than a mile. This gives you the most accurate reading, as driving heats up the tires and increases pressure. Outdoor temperature also impacts readings, with pressure dropping 1-2 PSI for every 10 degrees of ambient temperature drop.
You may need to make seasonal adjustments to keep tires inflated during winter cold snaps and summer heat waves. Visually inspect tires before getting readings, and check pressure immediately if you notice any damage or run over debris.
Finding the Recommended Tire Pressure
Before checking inflation with a gauge, you need to know your vehicle’s recommended tire pressure. The best place to locate this spec is on a sticker inside the driver’s side door jamb. This lists the proper inflation for the front and rear tires. You can also check the owner’s manual or tire placard.
The number shown is PSI – pounds per square inch. This is NOT the maximum pressure listed on the tire sidewall, which is much higher. Always follow vehicle manufacturer specs for proper inflation. Write the recommendation down so you remember while taking readings.
Getting Accurate Tire Pressure Readings
The two most common types of pressure gauges are analog with a built-in dial or pop-out stick, and digital gauges with an electronic display. Either can provide accurate readings if used properly. Here are some tips:
- Remove tire valve caps and place somewhere clean so they don’t get lost
- Press the gauge straight onto the valve stem, pushing hard to get a tight seal
- Hold briefly until the gauge registers – a small hissing sound is normal
- Read PSI on the display or gauge stick. Readings can be tough to see on stick gauges.
- For consistency, always take readings from the same spot near the valve stem
- Replace caps when finished to prevent dirt from entering
- Check remaining tires following the same procedure
- Retest any very low readings in case of a bad seal
The right gauge can last years. Go with digital for easy readings or dial for budget-friendly. Invest a few extra dollars for quality and accuracy. Avoid models with angled hard-to-read sticks. As a Mechanic, I recommend this budget friendly Tire Pressure Gauge for all your pressure needs. With thousands of happy customers, it’s a must have for any car owner.
Adjusting Tire Pressure – Adding Air
If the gauge shows tires under-inflated, add air using an air compressor at a gas station or a portable inflator. Align the inflator nozzle straight on the valve stem and press hard to seal. Add air in short bursts, rechecking with the gauge frequently to avoid over-inflation.
Set tire pressure to about 3 PSI above recommendations if adjusting when hot outdoors, then recheck when cold. Once inflated correctly, replace valve caps. For a full size spare, check regularly but avoid driving over 50 miles per hour.
Adjusting Tire Pressure – Removing Air
Use the release pin on the back of the gauge to depress the valve stem and slowly bleed out excess air if tires are over-inflated. You can also use a key or small nail. Press briefly and frequently recheck pressure to avoid releasing too much air. Never drive on over-inflated tires, which can reduce grip and wear unevenly.
Potential Signs of Improper Tire Inflation
Notice any of these issues? Improper inflation may be the culprit:
- Vehicle pulls to one side
- Uneven or rapid tread wear
- Low gas mileage
- Vibration or bouncing sensation
- Longer braking distances
- TPMS warning light illuminated
- Visibly low tire or “donut” shape
The Dangers of Under Inflation
Driving on under-inflated tires is extremely hazardous. Severe under-inflation causes excessive heat build up, which can lead to tire failure. The tread deforms more under load, wearing faster at the edges. Handling becomes loose, braking distances increase and you’re more likely to hydroplane. Fuel economy drops too.
If you notice vibrations or steering wheel pulling, you likely have a very low tire. Use a gauge to confirm, and inflate immediately or change to the spare if required. At minimum inflation, structural damage occurs. Regularly checking pressure monthly prevents this type of dangerous under-inflation.
The Dangers of Over Inflation
While not as risky as driving under-inflated, over-inflated tires still pose safety and wear concerns. Too much pressure causes tires to ride stiffly with less grip. The center tread tends to wear faster with less contact area on the road. Over-inflated tires are more prone to punctures and impacts too.
During hot weather, inflated tires expand to a higher pressure than when cold. Adjust to a few PSI under recommendations when hot out, and avoid exceeding maximum pressure listed on the sidewall.
Maintaining Proper Tire Pressure
Now that you’re armed with expertise on checking inflation, use these tips to maintain perfect pressure:
- Check all tires when cold once monthly or before long trips
- Use a quality pressure gauge – digital or dial type
- Inflate to vehicle recommendation, not tire maximum
- Adjust for temperature – add air when cold out
- Bleed air if over maximum inflation
- Recheck after any impacts or punctures
- Inspect tires regularly for signs of under inflation
Proper inflation maximizes safety, handling, tread life and fuel economy. By actively monitoring and maintaining manufacturer-recommended pressure, your tires will last longer and you’ll get the most out of your vehicle’s ride and handling. Let me know if you have any other tire pressure questions!
When to Seek Professional Help
While I encourage DIY maintenance, tire pressure issues can indicate other problems. Contact a professional technician if you experience any of the following:
- Repeated under-inflation with no leaks
- TPMS light stays on after inflating
- Visible tire or wheel damage
- Vibrations that won’t go away
The experts at Mechanic Answer offer affordable online guidance from professional mechanics. Get answers to your car questions anytime online from the comfort of home, or better yet, have the mechanic come to your home with our mobile mechanic recommendation service.
Don’t let improper tire inflation put you at risk on the road. Follow this regular maintenance routine for optimal safety, performance, tread wear, and fuel economy. Check inflation monthly when tires are cold, and adjust to the vehicle manufacturer’s recommendations. Invest in an accurate tire gauge, inflate low pressures, and bleed excess air if over maximum. Make tire pressure a priority for smooth handling, long tire life, and peace of mind behind the wheel.
Tire Pressure Frequently Asked Questions
How do you check tire pressure at a gas station?
Most gas stations have an air compressor you can use to check and fill your tires. Drive up close enough that the hose will reach all four tires. Insert coins if needed to start the compressor. Remove the valve cap from each tire and press the gauge on the hose straight onto the valve stem. Apply firm pressure for an accurate reading. Compare the PSI to your vehicle’s recommended tire pressure. Use the hose to inflate any under-inflated tires to the proper PSI.
How do I know if my tires need air?
Warning signs your tires need air include the TPMS light coming on, vibrations in the steering wheel, uneven tread wear, poor gas mileage, car pulling to one side, or tires visibly looking low. Use a tire gauge monthly when tires are cold to check inflation. Tires can lose 1-2 PSI per month through normal leakage. Always keep tires inflated to the vehicle manufacturer’s recommended pressure.
Can I drive with low tire pressure?
It's not recommended to drive with low tire pressure as this can be dangerous. Severely under-inflated tires risk overheating and blowouts. Handling is compromised, braking distances increase, and you're more likely to hydroplane. If a tire is very low but not flat, inflate to the proper PSI right away or change to the spare. Driving even short distances on very low tires risks damaging the tire structure.
How much air should be in tires?
The correct tire pressure is the PSI recommended by your vehicle’s manufacturer, usually found on a sticker inside the driver’s door jamb or in the owner’s manual. This spec is based on your vehicle’s model, tire size, and load capacity. Do not go by the maximum pressure listed on the tire sidewall, as this is too high. Maintain inflation within the recommended range.
Is 40 psi too high for tires?
40 PSI is likely too high for most passenger vehicle tires. The recommended pressure is typically between 30-35 PSI. Over-inflated tires reduce ride comfort, lose traction, and wear unevenly. Check what PSI your vehicle manufacturer specifies for proper inflation. It’s important to stay within their recommended range for performance, handling, and safety. Reduce pressure on any over-inflated tires.