[Pvmt-Pndr]

Since its only going to be used for your air horn I wouldn't get the biggest cfm you can find at all. I ran a small electric pump on a 3x horn setup for years with a 2 gallon air tank. I had a 140 pressure sensor in it. So what if it takes 2 minutes to fill the tank, you're not going to be blasting the horn constantly. I used the same small compressor when I made an 8 gallon tank that I could use to fill tires with.