The Truth about Tire Pressure (Tire Inflation)
August 28, 2022
Most light vehicles (under 10,000 pounds/4,500 kg) in North America sold from 2008 model year on have a feature that many people are confused about. It's the tire pressure monitoring system (TPMS). You may have some experience with it yourself if you own a newer vehicle. Vehicles with TPMS have sensors in each tire that are supposed to warn the driver when tire pressure gets dangerously low. That's important because tires that are significantly under-inflated can cause very serious accidents.
Unfortunately, many drivers think the TPMS does all the work keeping track of tire pressure. To them, as long as the warning light or gauge isn’t giving a warning, the tires must have the proper amount of air pressure in them. That's not the case.
Tire pressure monitoring systems aren't all created equal. Some give you a digital readout of the pressures in each individual tire. But many simply have a warning light that looks like the cross section of a tire with an exclamation point in the middle. If you don't know what it is, it's because it's not instantly recognizable as a tire. In fact, one company that makes TPMS, Schrader Performance Sensors, surveyed drivers. Their study showed that more than 40 percent of drivers didn't know that that warning light was.
One out of 5 of the drivers who did know what the light was only looked at their tires after the light came on to see if they could see any that needed air; they never checked them with a tire gauge or had someone else do it. Ten percent of them didn't do anything when the light came on.
In most vehicles with TPMS, the warning comes on only when the tires are more than 25% underinflated. The American Automobile Association says that's under the pressure you need for safe vehicle operation.
The bottom line is once a month you should make sure your tires are inflated to the manufacturer's recommendations. That means each tire should be measured with an accurate, external tire gauge. To be confident you are getting a correct reading, take your vehicle to a reputable service facility where their equipment is calibrated and they know what they're doing.
Severely underinflated tires can contribute to an accident that kills or severely injures people. The idea behind TPMS is well intended, but the system was never meant to replace regular inflation measurements and maintenance. Periodically have your tires checked for proper inflation.
Commerce Auto Repair
9575 Commerce Rd.
Commerce, Michigan 48382
248.363.3749
Need Service?
More articles from Commerce Auto Repair

A Most Important Part (Serpentine Belt Replacement)
October 27, 2025
Your vehicles engine is an engineering work of wonder with many complex parts working in harmony to get you down the road. One of those simple but important components is called a serpentine belt. It is driven by a pulley on the engine and transfers that power to many of your engines most importa... More

(Ball Joint Replacement)
October 23, 2025
Every day that goes by, our bodies get a little more wear and tear on them. Our vehicles have the same issue. The older we get and the farther we travel, certain parts start showing some wear. Think of your hips. There are parts of our vehicles that are similar to them; just like hips allow y... More

See the Light (Bulb Replacement)
October 12, 2025
When you notice one of your headlights has gone out, its important for the safe operation of your vehicle to get it changed and working again. Not only is replacing a headlight important for your ability to see in the dark, but its also vital that it be lighting your way and aimed correctly so o... More
