I haven't calculated it other than looking at my DIC. I am sick and tired of putting $700.00 worth of diesel a month in this truck, hell my payment is only $550.00. What are some good add-ons to get my mileage back up. I have 295's on it which are sucking diesel like a prom night keg. Not really wanting to remove the dpf. What are some realistic mods for me?