We have a 2015 30DS and are getting approx. 8mpg right now without towing a vehicle. We had a Sunseeker 2300 and averaged 10.5 mpg, but when we first got the Sunseeker, we only got 8.5 mpg. After it was broken in, it got 10 - 10.5 mpg with unleaded gas with
ethanol. When we used unleaded without
ethanol, it got up to 12 mpg. If you are using both kinds and getting 10 mpg on your FR3, that is great. I hope ours will get better mileage after it gets more miles on it, especially since we are having a towbar put on it so we can tow our Honda CRV. We are looking forward to putting lots more miles on it in the next few years!