mweiner Report post Posted July 12, 2017 On average, how many miles can you travel before you need to refill or add DEF fluid? I've been told that a full DEF tank of 5 gallons (US), will go approximately 4,000 to 5,000 miles? Have you had any experience with this? Maybe the Mercedes Benz Sprinter uses DEF more efficiently? Any thoughts? Share this post Link to post Share on other sites
jleamont Report post Posted July 12, 2017 Your engine, driving habits and weight will alter DEF usage, if there is a Roadtrek forum, you might get a better answer. Here's an example; the Ford Powerstroke manual states only adding DEF at service intervals, its vague across their GVWR's, while an F250 that drives to work every day, no load might be able to make it that long the F550 with a dump bed that hauls stones everyday will need to top it off every 1000 miles or so. Share this post Link to post Share on other sites
five Report post Posted July 13, 2017 It is virtually impossible to determine DEF usage other than doing it yourself in your coach. As Joe noted, it is very different for each vehicle. I've given up trying to determine usage, and keep the DEF level between half and 3/4, and always carry an extra 2 1/2 gallon jug from Walmart in the basement. Share this post Link to post Share on other sites
mweiner Report post Posted July 13, 2017 Thanks... yes, I carry extra DEF on board. Share this post Link to post Share on other sites
