Of all the things you have to look at when you try to choose an air compressor, the number of tanks seems like the strangest. Is there really a difference, given that compressor tanks can be made in several sizes? There are differences, it turns out, and they can have an effect on how you use the tank and even if you'll be able to use it at all.

More Air

As you'd think, a dual-tank compressor would hold more air because you could have two big tanks instead of one. This is a small difference, though, as you could also just get a big single-tank compressor. However, it is a difference to keep in mind when taking price and overall size into account. You could get a little more air power with a dual-tank compressor.

Better Balance

Dual-tank compressors do offer more stability and better balance. This is essential if you'll be using the tank on an uneven surface like a pitted dirt road or field. Many of the parts on dual-tank compressors sit lower, giving the apparatus a lower center of gravity. The two tanks also balance the compressor better. A single-tank compressor can be stable depending on the shape (e.g., pancake-shaped vs. skinny column), but a dual-tank compressor might be better if you need that stability.

Less Maintenance

One tank means less to maintain. If you don't want to deal with a lot of maintenance, a single-tank compressor will be easier for you to handle. With two tanks, you have the two tanks, two connectors, and two of several other parts. That's more that can break and cause you to have to take the tank in for repairs.

Backup Air

At the same time, two tanks means that if one malfunctions, you still have the other tank holding air and ready to go. If a single-tank compressor breaks, that's it -- it's unusable. Depending on what happens to a dual-tank, though, you could still be able to use it for a while before taking it in for repairs. This can be a questionable benefit, though, because you'd have to know which parts need to be working on both tanks to prevent malfunctions, bursting tanks, and so on.

Your best bet is to talk to compressor dealers and see which sizes and shapes they offer. Show them where and how you'll have to use the compressor, and for what, and they should be able to help you find a good one.