I've been averaging about 18 mpg according to the car but it does feel like less than that. I do mostly city driving and usually in sport mode once it warms up. I've noticed no gas smells or leaks of any kind. My engine is still fairly new at only 1600 miles so far.
I did run it very low on gas one time, so low that the fuel gauge didn't even have one pixel indicating gas. I pushed it for at least several miles that way before I finally found a gas station.
Ghibli S Q4 Nero Ribelle w/ Red Interior
Premium, Executive/Luxury & Sport Packages
Carbon Fiber & Alcantara Trim
Red Calipers w/ 20" Polished Urano Rims