tire pressure and temperature

Two seemingly unrelated pieces of your life: the weather is getting colder and your dashboard is telling you to check the pressure on your tires.

The truth is that tire pressure and temperature are intimately intertwined.

The questions seem endless. How? Why? Do I need to do something about it?

The answers are simple, and you’re in the right place to pick them up. Read on and we’ll discuss the ins and outs of your tire’s pressure and its relationship with the temperature outdoors.

Why Does Temperature Affect Tire Pressure?

Gay-Lussac’s Law.

Gasses aren’t a single uniform substance, instead, they’re made up of individual particles which move around in a relatively free manner depending on their density compared to their surroundings.

All particles are constantly in motion and temperature is a measurement of that motion.

The increase in pressure with increased temperatures comes from the particles colliding more frequently within the tire. The same is true for the reverse.

Basically: the amount of pressure in your tires is connected directly to the temperature.

It’s a basic law of chemistry. This isn’t a hypothetical either, it has a massive, observable effect in the real world.

How Much of an Effect is There?

For every 10°F, the temperature rises you’ll see a gain of about 1 PSI. The same is true for temperatures dropping, 10°F in the other direction and you’ll lose 1 PSI.

No matter how much awesome high-tech stuff is going on in the cabin and under the hood, your tires are going to fluctuate. There’s no way around it without being able to keep your tires at a constant temperature.

Temperature fluctuations through the day often have little effect on the tires as far as the driver is concerned. The big concern is when the seasons change.

Keep in mind that in most vehicles if your tire pressure light is on you’re looking at being at least 25% under pressure. That’s not normal and it can be a big safety issue if you ignore it.

Should I Air My Tires Back to Normal?

As a general rule, if the tire pressure light is on… you need to check the pressure and get things normalized as soon as possible. Being under pressure enough the car is warning you can cause some serious issues in the handling of your vehicle.

For most people, the answer is obvious: just fill it back to the normal 30-40 PSI range.

It’s the right move for the most part but in areas, with particularly extreme temperature fluctuations throughout the year, you may have to lower the pressure once the warm season begins again.

In milder climates, it’s usually not necessary, but it’s always a good idea to check your pressures monthly to make sure that your tires remain at the proper inflation level.

For most people, this only becomes a concern when the tire pressure light comes on. If your light isn’t on, you’re usually good to go and can make it back to the warm season without any extra maintenance.

What Happens With Low Tire Pressure?

Low tire pressure is a scourge on drivers.

When a tire is aired down too much a larger portion of it contacts the road. Your tires are designed to run within a certain PSI range by those who manufacture them and going outside of this tolerance range can have some nasty results.

Tire damage, lower gas mileage, and poor handling can all result from underinflated tires. You’re risking your tires and your life if you’re not making sure that your tires are inflated to the right pressure.

Indeed, almost 200 fatalities a year result from incorrect tire pressure.

Not being one of them is simply a matter of making sure that your tires are within an acceptable range.

What About High Pressures?

While it’s rare for a vehicle to reach pressures which are simply too high, it does happen.

You’ll have the opposite problem of too low of pressure: too little of the tire will be contacting the ground when you’re driving. The resulting loss of traction can cause poor handling for your vehicle and concentrates wear in a smaller area.

In extreme temperature fluctuations, it can even put you in danger of a catastrophic blowout.

How to Handle Tire Pressure Fluctuations

Unless your light is coming on regularly, a simple routine should help you avoid problems when it comes to tire pressure fluctuations.

Checking your tires monthly is your best bet.

In order to get an accurate result, you should have your own tire gauge.

The truth is that the ones which you find at gas stations should be a last resort. They’re used and abused to the point where they’ll generally only give you a rough estimate unless you happened to show up right after they were calibrated.

It’s also important to let the vehicle sit for long enough that your tires cool down. A couple of hours is the recommendation you’ll get from most mechanics.

The important thing is to make sure you’re in the range which is specified for your tires. Once you’re outside of it, things can take a drastic turn for the worst with little warning.

Tire Pressure and Temperature and You

The relation between tire pressure and temperature is easy enough to understand. If it gets too cold or hot and your TPMS light is flashing it’s time to change the pressure.

Your tires will last longer and you’ll be much safer while you’re driving.

If you’re looking for more quick fixes for your car, why not check out our car service and repair section?