I did close to that in my old pt cruiser. I carried about 1300 in mulch plus me. I had the seats folded down. God that car was terrible except for that
I own a 2017 kia niro touring launch edition and average about 43 mpg. I too notice once I start going over 65 I lose more mileage. I have 18" rims so I don't get as mileage as the 16 ones. Still pretty good though. Most of my miles are freeway about 45 during the week. I'm good with how many...