You can probably use the search capabilities of the forum here to find out more info, but to answer your question briefly.

OTR air (sometimes called bus air), is a very large (7 ton if I remember) compressor driven by the engine (via belt). It is the air conditioning system that you may be familiar with seated coaches, and is designed to cool a large bus, with a lot of people.

As part of the system, there are other components (consdensers, coolers etc) which take up at least most of one storage bay, perhaps more.

With OTR air, you would never have air conditioning issues when traveling cross country, even in extreme heat.

Objections to OTR include:

* generally had a large cost associated with it initially
* uses up some engine horse power
* loss of a storage bay


Some find it an absolutely essential part of their purchase decisions, while others dont.


Ray