The Best RV Tire Pressure Monitoring System

Here is why this is one of the few accessories we would call genuinely important. A trailer tire losing pressure gives the driver no feedback. There is no vibration through the wheel, no pull, no noise over road noise. The tire runs underinflated, builds heat, and comes apart — usually taking fender skirting, wiring and sometimes the side wall of the trailer with it.

A monitor tells you at the moment the pressure starts falling, when the fix is pulling over calmly.

Sensor count: do the arithmetic first

Most travel trailer owners want four or five. Buying a four-sensor kit and then wanting the spare monitored means buying a fifth sensor separately, which is usually fine but worth knowing before you order.

Monitoring the spare is more useful than it sounds. A spare that has been flat for a year is a spare that does not help you on the day you need it, and nobody checks it.

Cap sensors or flow-through

The flow-through argument is behavioral and it is a real one. If adding air means unscrewing a sensor, remembering the position, airing up and re-fitting, you do it less often. If it means putting a chuck on the sensor, you do it more.

The catch is the metal valve stem requirement. Many trailer wheels have rubber stems, and a flow-through sensor on a rubber stem flexes under centrifugal load and can leak or tear the stem. Changing to metal stems means a tire shop visit, which should be priced into the decision.

The monitor

A dedicated monitor sits on the dash or windshield, powered from 12 V, and shows all tires at once. It is always on and needs nothing from you. The downside is another thing on the dash and a cable to route.

A phone app saves the dash space and gives you a bigger screen. The downside is needing the phone paired and awake, and Bluetooth range from the back of a 35 ft trailer to the cab is marginal without a repeater.

For a long trailer, a signal repeater is often necessary whichever you choose. Budget for one if your trailer is over about 30 ft, and check whether the kit includes it.

What good alerting looks like

Pressure alone is not enough. The systems worth buying alert on:

• Low pressure, with a threshold you set per tire.
• High pressure, which rises with heat and indicates a problem if it goes far enough.
• High temperature, which is often the first signal of a failing bearing or a dragging brake — and that is a fault a pressure reading alone never shows.
• Rapid pressure loss, distinguished from slow loss, because the responses are different.

The temperature alert is underrated. A wheel bearing that is about to fail heats up long before anything else happens, and a TPMS sensor on that wheel sees it.

Batteries and maintenance

Sensors run on small coin cells, typically a year or two. Replaceable batteries are preferable to sealed sensors, and the better systems alert when a sensor battery is low.

Two habits: note the date you changed them, and keep spares. A sensor with a dead battery reads nothing, and a system you have stopped trusting is a system you stop looking at.

The verdict

Buy the four-sensor system with a dedicated monitor if you have a tandem-axle trailer and want the straightforward answer. Buy the six-sensor option if you want the spare and the tow vehicle covered. Buy the flow-through system if you have metal valve stems or are willing to fit them, because being able to air up without removing the sensor genuinely changes how often you check.