COMPRESSORS  Get the proper Compressor for what you are using it for.  Everyone says they have the best Compressor, and we are no exception.  The difference is that we have a complete lineup of compressors, each intended for a specific use.  The greater the CFM (cubic ft per minute) the faster it pumps up.  If you have a basic towing kit, or a trainhorn, you can use the smaller options, but if you have a full blown FBSS 4 corner Air Suspension Kit, you will need a larger 4CFM compressor to properly recover.  A 4CFM Compressor should be matched to a 3-Gallon tank.  You can use a smaller compressor, such as the Viair, or Zenith,  but it will take a while to fill, that is why they try to sell you 2 small compressors instead of our high capacity DC7500, which is 100% duty.  This means in theory it could run forever without tripping the circuit breaker.
Using a 5 gallon tank sounds good, but remember it will take twice as long to recover as a 3 gallon tank, therefore, a 5 gallon tank is best used with 2 LARGE DC7500 Compressors.

Another big mistake is to use a pressure shutoff switch which shuts off at over 150psi.  Your compressor simply works to hard after reaching the optimum pressure of 135psi.  If you need more psi than that, it means your bags are TOO SMALL in DIAMETER.  When you think of psi, think of blowing up a balloon and the increased back pressure as your lungs try to push back as your cheeks puff up.  Be sure you NEVER RUN A COMPRESSOR WITHOUT THE ENGINE RUNNING PRODUCING POSITIVE VOLTAGE.  You will burn it up....