Has this ever happened to you? You walk out to your car on a frosty winter morning, ready to head off to work, only to find one or more of your tires completely deflated. Annoying, right? But why does this happen, and what can you do to prevent it? Let’s take a closer look.
Here’s a quick answer:
Tires can deflate in winter because the air inside them shrinks when temperatures drop. This air contraction causes internal tire pressure to decrease to unsafe levels. Checking pressures often, proactively reinflating, using winter tires, and parking in garages helps safeguard against flats caused by air loss in frigid conditions.
Understanding Tire Pressure
First, a quick tire pressure basics refresher. Your tires are filled with air that is pumped in at a certain pressure. The recommended tire pressure for your vehicle can usually be found in the owner’s manual or on a sticker inside the driver’s side door jamb.
This pressure applies an outward force that helps your tires maintain their shape and grip the road properly. If the pressure drops too low, the tire can flex too much, causing damage or a blowout. The tire pressure also affects things like fuel economy, handling, and braking distance.
Why Tire Pressure Drops in Cold Weather
When temperatures take a nosedive in the winter, the air inside your tires actually shrinks. The colder it gets outside, the more the volume of air inside the tire decreases.
This causes the pressure within the tire to drop accordingly. Think of it like letting a little air out of an inflated balloon – the balloon starts to go limp. The same thing happens on a smaller scale inside your tires when cold weather hits.
Here’s a table showing how much tire pressure typically drops per 10 degree Fahrenheit temperature decrease:
|Typical Pressure Drop
So if it was 60°F when you last filled your tires to the recommended 35 psi, and then the temperature plummeted to 30°F overnight, you could expect those tires to lose around 3-4 psi by morning. For most passenger vehicles, that amount of pressure loss can cause a tire to appear nearly flat.
Preventing Flat Tires in Cold Weather
While you can’t control the weather, there are things you can do to help avoid flat tires in frigid temperatures:
- Check tire pressures often – It’s smart to examine all four tires at least once a month, but during winter you may want to inspect them more frequently. Identify and correct any pressure drops before they lead to flats.
- Fill tires proactively – Don’t just top them off to the recommended pressure. In especially cold regions, add 4-5 extra psi to account for pressure drops when temperatures take a dive. Then readjust in warmer weather if needed.
- Keep an air compressor handy – Totes portable mini air compressors designed for vehicles so you can reinflate as needed wherever you end up parked. Topping off a slightly low tire can get you home or to a shop.
- Use winter tires – Snow tires stay more pliable in freezing temperatures so they resist weather-related deflation better. Their deeper tread also grips better on snow and ice.
- Park in a garage – Protect your car and tires from the elements if you have access to a parking garage at home or work. Less exposure to the cold means fewer pressure drops.
- Add extra sealant – When installing new tires, request the shop inject extra sealant inside. This may prevent small punctures that lead to gradual air loss.
What to Do if You Have a Flat
Despite your best efforts at prevention, you may still end up with an entirely flat tire when cold weather hits. So what should you do?
If you notice significant air loss while driving, slowly and safely pull over to an area out of traffic. Hazard lights on! If the tire is still partly inflated, consider using that portable compressor to try reinflating enough to limp the short distance to a repair shop.
But if the tire is completely flat or damaged, you’ll need to swap on the spare tire or call for a tow. Standing out in the cold while changing a flat is zero fun, but safety first.
Of course, you can also practice changing a tire in warmer weather so you’re prepared for winter flats. Just be extra cautious when jacking up the vehicle on snowy or icy ground. Oh, and be sure to recheck the pressures and condition of those spare tires too!
Staying on Top of Tire Care
While nobody wants to think about flat tires in winter, a little proactive maintenance goes a long way. Check pressures often, keep an air compressor handy, use winter tires, and park in protected areas whenever possible.
And if you do end up on the side of the road with a flat, stay calm, get to safety, and take care of it. With vigilance and preparation, you can keep those tires inflated and rolling all winter long.
1. Does the type of tire matter in cold weather?
Yes. Winter or all-season tires are designed to remain more flexible than regular tires in cold temperatures. This prevents them from becoming too stiff and helps reduce the chance of air pressure loss in colder weather. They are your best defense against winter flats.
2. How often should you check tire pressures in the winter?
You should check all four tires at least once per month in the winter, as well as before any long trips. When temperatures fluctuate frequently, inspect them more often to catch any air loss early. Quick pressure checks take only minutes but could prevent being stranded with a flat.
3. What PSI level is best for winter driving?
For most passenger vehicles, you should add 4-5 extra psi above the recommended pressure listed on the driver’s door jamb or tire sticker. This gives your tires a buffer for natural psi drops that accompany cold snaps. Just don’t go higher than the tire’s maximum pressure rating.
4. Can you drive with under-inflated tires in the winter?
It’s not recommended. Every time you drop just 5 psi below the recommended pressure level, you increase fuel consumption and decrease safety. Under-inflated tires can cause flat spots, irregular wear, blowouts, reduced control, and longer stopping distance.
5. What should you do if you get a flat tire in freezing temperatures?
Slowly and carefully pull off the road and turn hazard lights on. If the tire still holds air, use a portable compressor to try inflating it enough to drive to a repair shop. If completely flat, loosen lug nuts while wheels are still on the ground, then install your spare tire. You should familiarize yourself with how to do this beforehand!