)5, 3500, 5.9, beefed 48re,triple disk converter, and better pressure body, hauling horses....now at 206,007 miles, and still getting from 12 MPG, when hauling 23,000. and about 22MPG when totally empty on I-5 north thru central valley. Totally stock engine, injectors, and running 15-40 Rosmella t5