One of the neat things about the four-wheel-drive industry being a part of the much larger automotive trade is the cross-pollination that occurs from segment to segment in the business. In many cases, the four-wheel-drive community benefits from technological advancement in other areas. A spin-off of run-flat capability in high-performance tires has provided a tool that serves as a valuable role in trailering your four-wheel-drive vehicle to the trail head. The ability of a run-flat tire to run for a number miles without any air pressure produced a need to indicate when a tire has lost air pressure. SmarTire USA stepped into the picture with a wireless system to monitor the pressure in your tires while you drive. This same technology is a natural for monitoring the tire inflation pressure on tow vehicles and trailers.
"But it's just another gadget!" scoff your friends. "How hard is it to occasionally check your tires?"
You might consider a wireless tire-monitoring system a gadget, but microwave ovens, cellular phones, and GPS units were once considered gadgets not so long ago too. While it is true that a simple round with a tire inflation gauge before embarking on the journey provides quick and easy tire pressure data, your knowledge ends as soon as the tires start rolling. Pick up a screw or a piece of wire on the highway, and a slow leak will result in a ruined tire unless you frequently monitor your tires while on the road. Visual checks are standard practice at fuel stops, but the distance between these are more than enough for a slow leak that could not be detected at your last stop to ruin a tire.
The workings of this idea are relatively simple. A small, lightweight transmitter is mounted inside each tire. A receiver is mounted inside the vehicle that provides a constant readout from the transmitters. The SmarTire RV-433 Tire Monitor System is specifically designed for light trucks and RVs and is capable of monitoring up to six tires.
The sensor modules are the heart of the system. Each module is only 4-1/2 inches long, slightly more than 1 inch wide, and weighs a mere 2 ounces. Inside this diminutive package is a pressure sensor, a temperature sensor, a motion sensor, a radio transmitter, and a long-life lithium battery. The sensors mount snugly to the rims using oversized hose clamps with corresponding counter weights to negate the need to rebalance the tires after installation. The tires are then mounted in the normal (albeit careful) manner.
The display module is slightly larger than a pack of cigarettes and about the size of a typical radar detector. Again, the small size packs a lot of features. The display shows four pieces of data for each tire at the touch of its two buttons: actual pressure, required pressure, pressure status, and temperature. In addition to the use of the buttons for manual display of information at any time, the display module also uses an alert light and a warning buzzer to automatically warn the driver of problems with tire pressure or temperature. The display monitor can be plugged into a power receptacle or hard-wired into your vehicle.