The United States has required tire pressure monitoring systems to be installed on vehicles for years. These are the systems that make a dash light glow if you have a tire with low-pressure. The problem with the pressure monitoring systems in many vehicles is that they don't say which tire is low, so if you don't have a tire gauge you have to continually go back and look at the dash light to see if the light goes off.
Nissan has installed a very cool and useful system on its 2013 Altima called the Easy Fill Tire Alert. The system comes as standard equipment on all 2013 Nissan models. The system works in much the same way as other similar systems on the market with a dash light that glows when a tire is low. When the driver begins to inflate the tires, the car's four-way flashers will flash to confirm the air is going into the tire.
Once the tires are at the proper pressure, the horn will chirp to let the driver know the inflation procedure is complete. That also means anyone can fill the tires to the correct pressure without having to know what the correct pressure setting is and without having to locate and fiddle with a tire pressure gauge. The Nissan system also tells the driver which specific tire or tires are low. If the driver happens to overfill the tire, the flashers blink faster and the horn beeps three times. The horn will chirp again, when the driver lets the air out of the tires to reach proper inflation. The only thing I wonder is if the system is adjustable. If the driver changes the factory tires, and those new tires have different pressure requirements, the system will need to be adjusted to function correctly.