Checking For Low Tire Pressure: No, You Can't Just Eyeball It

What is the right pressure for my tire?

Spring is upon us. Although, until it has sprung, most of us are stuck dealing with changing weather a while more. The hazardous driving conditions natural to this time of year increase the necessity of proper care of your tires. Unfortunately, braving freezing temperatures to check for low tire pressure is the last thing anyone wants to do.

Brave them you must though! Thanks to the pesky tendency of gases to expand and contract based on the temperature, the air you put in your tire during the last warm snap could be many PSI lighter in today's colder temperatures.

How To Check Your Tire Pressure

Get a tire pressure gauge  

• You can likely find a decent basic gauge for less than $3 with tax at the nearest gas station.
• Those who prefer a more modern tool can find a simple electronic tire pressure gauge with variable measurement units at any auto parts store.
• Jet-setters may prefer to go all-out on a set of Bluetooth connected valve stem covers that constantly monitor tire pressure, which sends data straight to your smartphone.

Find Your Recommended Tire Pressure

• Many modern cars will have the recommended tire pressure for your vehicle and tires printed on a sticker in the driver-side door jamb or in the vehicle's user manual.
• Or scan the information printed on the sidewall of the tire. Somewhere will be listed a minimum and maximum PSI rating for the tire, giving you an operating range.
• Especially on dirty, muddy, or just plain old tires, this can sometimes be difficult to read. Cleaning the sidewall and using a flashlight or smartphone light can help greatly here.

If Low, Refill to the Recommended PSI

• Few of us keep an air compressor handy. Luckily, virtually every gas station will have a free or extremely cheap station for filling. Be sure to bring your handy tire pressure gauge.
• Start by checking the pressure, filling the tire for 10-15 seconds, checking the pressure, and repeating until you reach the desired PSI.
• In case of overfill, use your pressure gauge to gently tilt the core of the valve, slowly bleeding air.

Why It Matters

"Look, I know my tire pressure is low. But it's freezing! Can't it wait?" Driving on a low tire for a day isn't the end of the world. Be careful that that one day doesn't become a week, a month, driving on a virtually flat tire until the entire tire fails, leaving you down a tire, a wheel, and hundreds or thousands of dollars in towing and repair costs. All to avoid, what? Being cold? Buying a $3 tire pressure gauge? On top of all that, Mr. Right has compiled a list of the adverse effects of driving on a low tire including:

• Low gas mileage: The US Department of Energy estimated that every one PSI below the proper level decreases your MPG rating by 0.2%.
• Decreased tread longevity and Increased risk of tire failure: Under-inflated tires have increased contact with the road. This increases friction, resulting in increased wear on your tire treads. You will surely be replacing the tire sooner than if you had kept it properly maintained.
• Decreased control: In poor road conditions, under-inflated tires are more likely to spin out in rain or ice. Additionally, your car will be slower to stop when braking.

The short-term benefits of procrastinating until it's warmer are far outweighed by the drawbacks and dangers of driving with low tire pressure.