I ran e85 in my old dodge, 318 2002 van,B3500. Maybe 10 tank fulls , and it never ran rough, but the mileage went down the tubes bad. I ran E85 and regular gas mixed 50/50 and still got bad mileage, like 10mpg, with regular gas it got 15mpg max. Of course my van weighed in at 5700 pounds unloaded and usually I hauled 2500 lbs most of the time in the box. The engine let go at 300k miles due to oil pump failure, ticked me off. It should have gone 700k, but life goes on.