When it’s time to decide whether you want to pay extra to put nitrogen in your tires, there are two questions you need to remember.

Number one: Is it better? The answer to that is yes.

Number two: Is it worth the extra cost? Easy, the answer to that is no.

So if it’s better, why isn’t it worth the extra money? Because nitrogen is not significantly better than plain old air and simply checking your tire’s pressure every now and then is a lot cheaper.

Let’s start with explaining why nitrogen is better. It’s more stable than regular air (which is already 78% nitrogen). The molecules are fatter than oxygen so they don’t leak out as easily.  As a result, your tire will lose less pressure over time. Also, the oxygen content in your tire’s air can cause an accumulation of moisture which can create corrosion in your wheel (the metal part, not the rubber).

Nitrogen is always used at the highest levels of racing because they depend on the tire maintaining it’s pressure. If the team decides to raise or lower the pressure by half a PSI (pound per square inch) to change the handling, they want to know that’s exactly what they’re getting. Because nitrogen is less susceptible to temperature, the pressures are also more stable during the race.

That’s great for the Indy 500, but it’s not so critical for the tires on your car. Don’t get me wrong, you want to have the right air pressure. Running too low or too high can cause early tire wear or, worse yet, create a handling problem. But the reality is that air loss for the average tire is so small that monthly checks with a simple tire gauge are more than sufficient (assuming you don’t have some type of leak).

Besides, a year-long study by Consumer Reports back in 2007 found that tires filled with nitrogen still leaked. It wasn’t as much as in the tires filled with regular air, but the nitrogen didn’t eliminate the need to regularly check air pressure.

There’s also a question about whether the moisture build-up in a wheel is actually a concern. These days most wheels are alloy and corrosion just isn’t a problem. I worked my way through college as a tire buster at Sears Automotive and I don’t remember a crisis created by rusty wheels corroded by moisture.

According to the GetNitrogen.org website, it should cost between $3 and $10 to switch to nitrogen. Unfortunately, I’ve also heard of some places that charge a lot more. Which means that the salesman pitching the nitrogen upgrade may be more interested in profit that safety.

As with so many things, it simply comes down to the cost/benefit ratio. Is nitrogen so much better that it’s worth the additional cost? If you’re running a fleet of trucks around the country and racking up thousands of miles every day, the answer is probably yes. But if you’re just an average driver, then the answer to that is likely no. Invest in a decent tire pressure gauge and make sure you check your air on a regular basis.

It doesn’t sound nearly as cool as having nitrogen filled tires, but it’s definitely a lot cheaper.

Here’s an article from Edmunds.com about the pros and cons of nitrogen.