I believe you should just look here.http://www.airhornsoftexas.com/train/train.html?gclid=CKTUqpW7l4oCFRhFVAodEWlMnw
If we cut down on our gas tank - we would have to stop as often as those with 1800'S
Marigold, I don't think two Stebel horns will be any louder than one. The decibels are not cumulative when adding another horn. At least I think I remember reading this somewhere on the big board when I put the Stebel on my X.