The biggest advantage of using air powered tools is that they have much more power than traditional electric powered tools. If you need to secure the tire back on to your car, then only an air powered ratchet will provide the safest, tightest fit. However keep in mind that in this case you will need a good, solid T-wrench and a lot of elbow grease to get it off by hand. You may want to consider keeping a T-wrench and extension (any hollow pipe that increases your lever arm) in your trunk for an emergency.

If you are looking for a compressor to power your various tools then you should become familiar with some abbreviations that are essential to understand. The first is CFM, which means cubic feet per minute and the second is PSI, which means pressure per square inch. Both these terms describe the air flow and power that the compressor is capable of and knowing how muh of them you need will tell you what kind of compressor to buy.

Most household tools only need 5 CFM and 80-90 PSI, however some larger tools may need as much as 10-12 CFM and 100-130 PSI. You will need to check tools that you already have or want to buy for their requirements. There is nothing wrong with buying a compressor that is too powerful, besides of course that it will probably cost more. If you have some old air tools and you aren’t sure what they need than here is a general list from my experience:

(CFM estimates assume 90PSI)

Angle Disc Grinder – 7″ 5-8
Brad Nailer 0.3
Chisel/Hammer 3-11
Cut-Off Tool 4-10
Drill, Reversible or Straight-Line 3-6
Dual Sander 11-13
Framing Nailer 2.2
Grease Gun 4
Hydraulic Riveter 4
Impact Wrench – 3/8″ 2.5-3.5
Impact Wrench – 1/2″ 4-5
Impact Wrench – 1″ 10
Mini Die Grinder 4-6
Needle Scaler 8-16
Nibbler 4
Orbital Sander 6-9
Ratchet – 1/4″ 2.5-3.5
Ratchet – 3/8″ 4.5-5
Rotational Sander 8-12.5
Shears 8-16
Speed Saw 5

One final number that you will often see talked about no matter what you need the compressor for is tank size. Many models boast large tank sizes as a big selling point, but really it is not that important. In fact, I would say that if you need the air compressor to be portable than just get a small tank (2-5 gallons). However if you plan on working with air tools extensively than a larger tank is nice because the unit will not have to run as much, and they are usually loud. Also, if you are using a tool consistently for a prolonged time (i.e. sander) than it is good to have a big tank to maintain the proper pressure the whole time you are working.