The engine is a 6.7L Duramax paired with the Allison transmission. The rig is a 2007 Jayco Seneca 34SS. I have the same setup in my 2008 GMC 2500 Sierra and have run almost dry routinely. Tank capacity is only 25 gal, however. I am about to have the Seneca serviced after 4000 miles, I'll ask about the filters.