External vs. Internal TPMS Sensors: Which One is Right for You?

A tyre pressure monitoring system (TPMS) is an aftermarket solution which uses sensors to measure the real time air pressure inside each tyre.

There are two main types of TPMS sensors - external and internal - and each comes with its own unique benefits. External sensors are fitted on the outside of your vehicles and replace the air valve cap - effectively doubling as both a sensor and an air valve cap. Internal sensors are fitted onto the inside of the tyre.

In this post, we’ll break down the areas where each shine. Whether you prioritize ease of installation or long-term durability, understanding the benefits of each can help you make a smarter, safer choice.

Battery Life

The battery on external sensors typically lasts 2 years. Once the battery runs out however, you can buy replacement batteries to keep it going. Internal TPMS sensors, on the other hand, are powered by longer-lasting batteries. These sensors have a typical battery life of 6 or more years, depending on driving conditions and usage. They’re designed to work reliably for a large portion of your vehicle’s life without needing attention. However, the batteries on internal sensors cannot be typically replaced.

Verdict: Internal Sensors win for battery life. If long-term battery performance is a top priority, internal TPMS sensors are the clear winner. Their built-in power source is designed to go the distance - making them ideal for drivers who want a set and forget solution.

Ease to Install

One of the biggest differences between external and internal TPMS sensors is how they’re installed. External TPMS sensors are installed by screwing them onto your tyre valve caps - simple as that. There’s no need to remove the tyre or visit a mechanic. It’s a perfect DIY solution for everyday drivers, road trippers or fleet managers who need a fast and flexible setup. Internal TPMS sensors, however, require a more involved process. Because they’re mounted inside the tyre, installation typically needs to be done by a professional. This means taking the tyre off the wheel, fitting the sensor and then rebalancing the tyre. 

Verdict: External Sensors win for ease of installation. If you want a hassle-free setup you can do yourself without tools or a trip to a tyre shop, external TPMS sensors are the clear choice. They offer instant installation and easy transfer between vehicles.

Durability

When it comes to long-term performance, external TPMS sensors are exposed to everything the road throws at them - rain, dust and snow. While high-quality external sensors are built to be weather resistant and tough, their location on the valve stem makes them more vulnerable to physical impact, corrosion and general wear over time. Internal TPMS sensors, in contrast, are safely housed inside the tyre - protected from harsh weather and road debris. This makes them highly durable and reliable over many years, even in extreme climates or rugged driving environments.

Verdict: Internal Sensors win for durability. If you’re looking for maximum protection and longevity, internal TPMS sensors are the better choice. Safely shielded inside the wheel, they’re less prone to damage and degradation.

Accuracy in Extreme Conditions

Tyre pressure is even more important in extreme conditions like high-speed driving, off-roading or extreme heat and cold. External TPMS sensors measure air pressure from the outside of the valve stem, which can introduce slight delays or inaccuracies due to environmental exposure. While external sensors are more than precise enough for general use, their positioning makes them slightly more vulnerable to inconsistent data in extreme environments. Internal TPMS sensors measure pressure and temperature directly from inside the tyre - providing real-time and highly accurate readings under all conditions. Whether you're climbing a mountain pass, hauling heavy loads, or driving long distances at high speed, internal sensors offer more stable, precise data all the time.

Verdict: Internal Sensors win for accuracy in extreme conditions. When accuracy is critical - whether for towing, performance driving or harsh environments - internal TPMS sensors are the top performer. Their direct line of measurement and insulation from external variables make them more reliable under pressure.

Risk of Theft

When investing in a TPMS, it's important to consider how secure your sensors will be once installed. External sensors, while convenient and easy to install, are also more vulnerable to theft or tampering since they’re exposed. Anti-theft lock nuts can deter removal, but they can’t eliminate the risk entirely. Internal TPMS sensors, on the other hand, are completely hidden and inaccessible once installed. They're mounted inside the tyre so they can’t be seen or removed without taking the tyre off. As a result, internal sensors are virtually theft-proof and offer a greater sense of security for long-term users.

Verdict: Internal Sensors win for theft protection. If theft prevention is a priority, internal TPMS sensors are the clear winner. Their concealed placement inside the tyre makes them extremely secure.

Compatibility with Tyre Types

Both external and internal TPMS sensors are generally universally compatible with any standard tyres. This includes cars, SUVs, trucks, motorhomes, trailers and even some motorcycles. 

Verdict: Equal on this front.

Maintenance Requirements

External TPMS sensors may require some level of upkeep. However, due to easy accessibility, this is straightforward and rarely will there be situations where heavy maintenance is required. Internal TPMS sensors require virtually no maintenance once installed. Their sealed design protects them from the elements.

Verdict: Generally equal but internal sensors have a slight edge.

Ease to Inflate

External TPMS sensors sit directly on the valve stem, which means you’ll need to unscrew and remove each sensor before inflating the tyre. While it only takes a few seconds per tyre, it can become a minor inconvenience. However if you’re using anti-theft lock nuts, the complexity and time is increased. Internal TPMS sensors, however, are mounted inside the tyre and don’t interfere with the valve stem at all. This means you can inflate your tyres just like normal - no extra steps and no parts to remove.

Verdict: Internal Sensors win for inflation convenience. When it comes to tyre inflation, internal TPMS sensors offer the smoothest experience. There’s no need to remove anything and access to the valve stem is always clear.

Conclusion

Both external and internal TPMS sensors offer valuable benefits - but the best choice depends on your driving habits, vehicle type and personal preferences. If you’re after quick installation and DIY, external sensors are a smart, flexible option. On the other hand, if you value long-term durability, precision under extreme conditions and peace of mind, internal sensors are the clear winner.