Top 5 Pitfalls When Buying TPMS - The 3rd One Is a Must-Know

Buying a Tyre Pressure Monitoring System (TPMS) might seem straightforward, but choosing the wrong one can lead to inaccurate readings, poor battery life or simply a system that isn’t suited to your needs.

With many TPMS options available, it can be difficult for people - especially those seeing TPMS for the first time - to understand what really matters beyond price and basic features. In this guide, we’ll cover the top 5 pitfalls to watch out for when buying a TPMS, including one overlooked issue that could make a big difference to how easy your system is to use.

TPMS come in 2 forms - direct branded replacements (like factory direct ones for Toyota, Hyundai, etc.) and aftermarket TPMS. Direct replacements are typically only the sensors (since it connects directly to the vehicles dashboard) while aftermarket ones come with sensors and a separate display monitor to show the tyre pressure data.

1) Battery Life and Serviceability

Battery life is an important consideration when buying a TPMS - particularly if you’re choosing external sensors. As a general guide, look for at least 2 years of battery life for external sensors and at least 5 years for internal sensors.

For external sensors, it’s also important to make sure the battery is replaceable. A replaceable battery means you can continue using the sensor rather than having to replace the entire unit when the battery runs out.

2) Environmental Resistance

A TPMS needs to withstand more than just everyday driving - especially in Australia, where sensors can be exposed to rain, dust and mud. For this reason, look for a system with an IP67 rating. This means a device is fully dust-tight and can survive being submerged in up to 1 meter of water for up to 30 minutes.

It is particularly important for external sensors, as they are mounted directly onto the valve stem and are exposed to the elements. Without adequate environmental protection, moisture and debris can potentially affect sensor performance and reliability over time.

3) Sensor Type: Internal vs. External

When choosing a TPMS, you’ll have two options: external or internal sensors. Internal sensors are fitted inside the tyre and typically require professional installation. If you choose an internal system, look for one with Wireless Sensor Pairing. This makes a big difference if a sensor needs to be re-paired, the tyres are swapped or a sensor is accidentally deleted. Without wireless pairing, re-pairing an internal sensor may be difficult and can potentially require the tyre to be removed again.

Internal sensors also have the advantage of not interfering with normal tyre inflation or deflation and are naturally protected from the outside environment.

External sensors, on the other hand, are much simpler to install. They simply screw onto the tyre valve stem in place of the standard valve cap - allowing most users to install them themselves in a few minutes.

Branded replacement TPMS is typically internal sensors only. Aftermarket systems allow you to choose between internal or external sensors. External sensors are significantly cheaper and far less hassle to install than internal sensors - particularly when you factor in the cost of professional tyre removal and installation.

4) Accuracy & Pressure Limits

Accuracy matters when it comes to tyre pressure monitoring. A TPMS with a large pressure tolerance can give you readings that are noticeably different from the actual tyre pressure. As a general guide, look for sensors with a pressure tolerance of 1-2 PSI or less.

It’s also important to make sure the TPMS is rated for the pressures your vehicle uses. Passenger-vehicle TPMS systems typically monitor pressures up to 99 PSI, which is more than suitable for most cars, 4WDs, trailers and caravans. However, trucks and heavy vehicles can run significantly higher tyre pressures, so TPMS for these vehicles should be capable of monitoring up to 200 PSI.

5) Signal Range

Signal range is another important factor to consider when choosing a TPMS - particularly if you’re monitoring multiple tyres across a longer vehicle.

As a general guide, look for a TPMS with a signal range of at least 10 metres by itself. This is the distance from your TPMS display monitor to the furthest sensor. It should cover most regular passenger vehicles plus vehicles with shorter trailers.

If you’re towing a longer trailer or caravan, or your vehicle has potential sources of signal interference such as metal components or other electronics, a longer range may be required. In these situations, look for a signal booster that can increase monitoring range to at least 20 metres.