Tire Pressure Monitoring Systems (TPMS) have become a critical tire safety feature on modern vehicles, preventing many accidents and ultimately, saving many lives.
But what exactly are these systems, and how do they help? Learn the ins and outs of TPMS, including how these systems have evolved over the years, what kind of periodic maintenance they need, and the top 5 things you should look for in an aftermarket upgrade.
How Do TPMS Work?
TPMS consists of sensors that measure and monitor your tire’s air pressure.
These sensors are located in the vehicle’s wheels, where they are pre-programmed with a set range of safe tire pressures. If the pressure drops too low (or registers too high), these sensors send an alert to the car’s dashboard so the driver knows there is an issue.
Some TPMS sensors can also be programmed to monitor and detect temperature. This is important because tire pressure is easily affected by ambient temperature. Other sensors can detect leaks or faults in the tire as well – also useful information to have, especially when traveling at highway speeds.
Tech Tip: Tire pressure is measured in PSI, which is the minimum amount of air pressure needed inside the tires in order to support your vehicle when it is at its maximum load. You can find your vehicle’s recommended PSI listed on the sticker on your driver’s side door or in the owner’s manual.
Why Are TPMS Important?
Good TPMS offer benefits for you and your vehicle, including improved fuel economy, extended tire life, improved safety, and environmental efficiency.
Better Fuel Economy. Under-inflated tires have a larger contact patch with the road, which means they require more force to roll over the surface. This is useful in some off-road situations, when drivers need to create more traction. But for everyday drivers, it just makes their vehicles work harder – burning more fuel in the process.
Longer Tire Life. Under-inflated tires can also lead to more or uneven tire wear, as well as cracking or even dangerous blowouts. In fact, it is under-inflated tires – not punctures – that are the leading cause of tire failure. It’s important to note that over-inflated tires can be dangerous too, as they are more susceptible to damage from debris or potholes.
Improved Safety. Just like worn-out sneakers can really take a toll on a runner’s feet and joints, worn-out tires do a number on your vehicle’s handling and braking performance. With properly-inflated tires, you can more safely navigate all the things the road throws at you and ensure other systems don’t need to work so hard to compensate.
Less Pollution. As noted, your vehicle must work harder to maintain speed when tires are improperly inflated. This requires it to burn more fuel, which pumps more harmful gases into the atmosphere. By having properly inflated tires, you help to reduce emissions of dangerous pollutants.
A Brief History of TPMS
You might be surprised to find out that TPMS is a relatively new innovation, originating on European luxury cars in the 1980s. The first American car equipped with TPMS was the 1991 Chevrolet Corvette.
It wasn’t until September 2007 that all newly manufactured cars in the U.S. were required to have TPMS – even later for Europe and China.
Mandating TPMS in the states was a result of the Transportation Recall Enhancement and Documentation (TREAD) Act. Those of you old enough to remember the Firestone tire recall of the late ‘90s might be familiar with TREAD, as it was passed by Congress after hundreds of people were injured or killed in accidents caused by the defective tires.
TREAD required that a tire warning system be installed on all light motor vehicles (under 10,000 pounds) that would alert drivers of inflation issues. Just 5 years later, NHTSA determined that the presence of TPMS reduced the chance of severely underinflated tired by 55.6%.
RVs and trailers are still not required to have a TPMS, although many manufacturers and customers choose to either build units with TPMS or add them aftermarket for safety.
Tire Minder RV TPMS
Throughout the past 10 years, TPMS has evolved to accommodate new technology and improve safety. Innovations include programmable TPMS, aluminum adjustable stem options to better accommodate tire changes, and more detailed sensors that can detect information like temperature, location and acceleration.
Direct vs Indirect TPMS
The two main types of TPMS are direct and indirect systems.
Direct TPMS, which are the more common (and more accurate) type, rely on pressure sensors mounted inside each tire to measure and monitor air pressure and temperature. These sensors then send this data – wirelessly and in real-time – to a control module inside the vehicle. The module is what alerts you if the tire pressure drops below a certain threshold.
Indirect TPMS works a little differently. Rather than measure air pressure with physical sensors in the tires, it instead uses the wheel speed sensors via the vehicle’s Anti-lock Braking System (ABS). This allows it to detect variations in the wheels rotational speed that could be caused by tire pressure.
As you can imagine, this is a less accurate method of measurement – and a driver may have to travel quite a distance before the alert pops up regarding low tire pressure.
As a result, Direct TPMS systems are the most common type of TPMS system found in vehicles by an overwhelming majority.
Current TPMS usually sends tire pressure information via radio frequencies. However, as Bluetooth technology evolves, it continues to replace these older transmission methods.
In addition to providing two-way communication, Bluetooth systems tend to have longer battery lives; the ability to sync with convenient smartphone apps; over-the-air update capabilities so users can download new features as they become available; and enhanced cybersecurity authentication (to help prevent hacking).
Proper TPMS Care
Built-in sensors’ lithium-ion batteries have a relatively long life of five to ten years, but it’s often recommended that the TPMS be serviced after changing or installing new tires or wheels.
In the case of a new set of tires you should consider replacing the valve core, retaining nut, and seal and cap on the valve stem, then testing the system to make sure it’s operating correctly.
If a TPMS sensor goes bad for any reason, the cost to replace them can range from $50 to $100 depending on your vehicle. Most often you will want to take your vehicle to an automotive shop for TPMS replacement, but you are able to do it yourself at home with some study.
There are available standalone TPMS tools that have basic diagnostics capabilities. You simply plug the tool in and scan each tire’s TPMS sensor. Your vehicle then learns and registers the sensor position and PSI almost instantly. The tool is compatible with most OEM vehicles for all domestic, Asian, and European makes and models. It also works with many aftermarket applications.
Aftermarket TPMS
If you have a vehicle that was manufactured prior to 2007, it may or may not include TPMS. If not, you may wish to add TPMS to your vehicle – especially if you will be towing frequently or using an RV.
There are 5 things you should look for in an aftermarket system:
Vehicle compatibility. Most aftermarket applications work with a wide variety of vehicles, using sensors that can be programmed to various vehicle makes and models.
High-quality sensors. There are various high-quality sensors available on the market. They come in two different aftermarket applications: Pre-programmed sensors and programmable sensors. Pre-programmed sensors already have multiple year, make, and model (YMM) vehicle types preloaded in. Programmable sensors are effectively “blank,” and allow a user to customize them with the specific vehicle’s YMM using a special tool.
Battery life. Be sure to look for a TPMS sensor with long battery life, so you won’t have to have replacement sensors which can add up quickly. Typical battery life is between 5-10 years.
Ease of installation. You can choose to have your aftermarket system installed professionally with a dealer or automotive shop, or you can choose to do it yourself. If that’s the case, you’ll want to look for an aftermarket TPMS solution that is easily installed.
Value. Lastly, consider cost when deciding which TPMS system to purchase. Consider what you need from your TPMS, whether that’s multiple features or more of a basic setup. But keep in mind that TPMS is integral to keeping yourself and others safe on the road, so be sure to pick a system with reputable safety.