It’s tire pressure light season in Alabama!

Many will notice their tire pressure lights coming on with the chilly mornings we’re set to have

It’s tire pressure light season in Alabama!
Cold WX Tire Pressure

MONTGOMERY, Ala. (WSFA) - Did your tire pressure light come on this morning? If so, you certainly weren’t alone. Temperatures fell into the 40s in most locations for the first time since mid-May.

Temps that low will cause even the best, newest tires see their pressure levels drop a bit courtesy of the molecules within your tires huddling up and moving slower than normal. The bad news is a dashboard light coming on in your car usually always means some sort of attention is needed -- in this case it’s just more air.

But the good news is seeing your tire pressure drop this time of year is perfectly normal and expected.

Tire pressure values fluctuate by roughly 1 psi for every increase or decrease of 10 degrees.
Tire pressure values fluctuate by roughly 1 psi for every increase or decrease of 10 degrees. (Source: WSFA 12 News)

But how is an alert light coming on normal?

It’s quite simple...

Your tire pressure is still in “summer mode." In other words, your the pressure in your tires is set to be “normal” for hot temperatures during the day and mild temperatures at night. Now that we’ve seen a morning in the 40s (with more to come), your tires lost pressure because they aren’t in fall mode yet.

Tires typically lose about 1 psi for every temperature drop of 10 degrees. So when we go from 90 on Monday to the 40s this morning, your tires likely saw a drop of roughly 3-6 psi. That drop won’t last, though.

Most vehicles have tire pressure values between 30 and 35 psi.
Most vehicles have tire pressure values between 30 and 35 psi. (Source: WSFA 12 News)

That’s because after cool to chilly starts, we’ll see temps rise into the 70s each afternoon for the next week. That increase of about 20-30 degrees between morning and afternoon will allow your tires to see their pressure increase by 2-4 psi from the time you leave for work to the time you leave work. You may also notice an increase of 1-2 psi just by simply driving your vehicle for 10-20 minutes as the air warms and expands inside your tires.

Thus, it’s very possible that during the warmer afternoons, your tire pressure light turns off without you actually doing anything.

Even if that happens, you should still strongly consider adding air to your tires as October gets underway.

That’s just due to the fact that we are likely to continue seeing cool nights and not-so-hot afternoons for the foreseeable future. Not only that, but the even colder weather of November and December will be here before we know it -- unfortunately.

Tire pressure lights come on more often during the fall because temperatures start dropping. Here's what to know...
Tire pressure lights come on more often during the fall because temperatures start dropping. Here's what to know... (Source: WSFA 12 News)

Most vehicles suggest keeping your tire pressure between 30 and 35 psi, with most in the 32-35 range. If you’re unsure of your vehicle’s suggested tire pressure, you can find it on a sticker inside the driver’s door, or by consulting your vehicle’s manual.

If you notice your pressure down in the upper 20s (or if your tire pressure light comes on) during these cool mornings, it’s a good idea to add some air because even the heating of the day won’t get you up to where you need to be in most instances. And it’s vital to have adequate amounts of air in your tires because low pressure can result in less-than-ideal driving conditions...

  • Poor fuel economy
  • Shorter lifespan of your tires
  • More time to come to a stop

Be careful about when you filly our tires, though! It’s suggested to fill your tires during the morning or after your vehicle has been sitting in a shaded area for 4-6 hours because the manufacturer’s suggest psi numbers assume “rested tires,” or tires that are cold.

So pick a morning over the next week and add air until your tires are at their recommended psi level. This will ensure correct psi levels for these cooler mornings. Again, it may only be an addition of 1-3 psi per tire, but that could prove costly in the long run!

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