Hello everyone. I was hoping I could get some advice on some issues I am having. I recently purchased a 2019 Mustang Ecoboost with 30k miles on it. The first couple of months I had it things were going pretty well. I haven't done any mods yet as I was waiting for some nicer weather. Oddly, my MPG has decreased pretty dramatically the past 6 weeks. Nothing has changed in my driving habits, tire pressure is good, filters are clean but I am getting a combined 20 MPG. Most of my mileage is highway and I was getting closer to 30 MPG until the last month and a half. On top of that, my car has started to get a bit jumpy out of first and when downshifting. Nothing major, just different than it was when my MPG was normal. Took it to a mechanic yesterday who couldn't find anything wrong with it. Anyone have a similar experience? Any advice? Thank you so much for your time.