Car Coach Lauren Fix answers your questions about car buying and maintenance. This week, Lauren talks about tire pressure, keeping your self safe, and your car achieving the best fuel economy it can.

Dear Car Coach:

I know that tire pressure is important, but I don't even own a tire pressure gauge and instead rely on my mechanic to do it whenever I remember to stop. My tire pressure monitoring system on the dash is confusing when the light clicks on. Is there a better way to check tire pressure? QL

Dear QL:

While the government-mandated tire-pressure-monitoring-systems on all new cars is a good idea on paper, in reality it fails miserably. A single light on the dash leaves you guessing which tire is low on pressure. Often, Tire Pressure Monitoring Systems (TPMS) erroneously warn drivers of low tire pressure all the time even though the tires are fully inflated. Sometimes your light may turn on when the temperatures outside change dramatically from morning to night.

Some high-end cars, as well as a few moderately priced cars (like the Nissan Altima) will actually tell you which tire is low and by how much via a digital readout on the dash. While this is an improvement over the single warning light, too few vehicles actually have such systems. Inevitably, drivers end up ignoring their tire pressure lights rather than checking each tire manually with a gauge. And that's how many people end up driving around on under-inflated tires.

Many serious bicyclists know that tires should be checked and topped up each time they go out on the road. I have always been a big proponent of checking your tire pressure on at least a monthly basis. Not only do properly-inflated tires save fuel, they are also safer and will last longer.

Nissan has invented a foolproof system whereby drivers can never over-inflate their tires and will always know which tire needs air and when. The beauty of this system is that you never need a gauge, which most drivers don't have anyway. All you need to do is fill the tire and the car's horn will honk when it's full. The system is on the Quest minivan and Altima sedan, and Nissan is moving to make its Easy Fill Tire Alert system standard equipment on its 2014 model year vehicles.

Since you don't have this system, I strongly urge you to buy a simple tire gauge, which will cost you less than $10. Keep it in the glove-box. One Saturday a month, take ten minutes to check your tire pressure, oil and washer fluid. Europeans, especially Germans, are famous for taking care of their own basic maintenance in this way, but it's become a bit lost in our modern American culture.