On any stop, whether it be a campground or fuel stop, highlight or click that stop in the Trip menu on the left. A series of small icons will appear to the right of that stop, click the pencil icon. You'll see a field for Fuel Cost/Gallon. Enter the value you wish and click Save.
2015 Tiffin Phaeton 42LH - All Electric w/tag
2016 Jeep Wrangler Unlimited Sport