Ford 6.0 liter and 6.4 liter diesels were trouble. The Ford 6.7 which came out in 2011 has been an excellent engine. In 2015 it was upgraded slightly to make it even stronger. The main improvement was a different turbo which provides for better exhaust braking. The newer Rams, especially with the Aisin transmission are equally as good. The Duramax/Allison has been very goid and especially since 2006.