I just learned that annually a Fire Fighter training convention happens in Indianapolis, called the FDIC

Images from http://www.globalemergencyvehicles.com/blog/fdic-2014-highlights/

And this website, Global Emergancy Vehicles has a comprehensive look at the many varieties of Ambulances, fire trucks, etc... like which makers have better engines, and why http://www.globalemergencyvehicles.com/blog/tips-buying-used-ambulance/  (buy a Sprinter or Ford with the 7.3L diesel)

if you're interested in fire trucks, how fire depts plan to replace and lease vehicles :  http://www.fireapparatusmagazine.com/archives.html

Above 3 photos found on http://chicagoareafire.com/blog/2014/04/more-from-the-2014-fdic/