The MDS really helps for sure. I have a '18 Mustang GT we just took on a trip out west a couple weeks back. Hand calculated mileage on a couple legs across South Dakota at 80+ miles an hour, cruise and AC on.....25-27 mpg. Not bad for 460 hp with no MDS/DOD..I was very happy!
with most modern muscle cars that mileage is about normal for highway driving.
i get 25mpg, hand calculated, on the freeway, 70+ mph, on long trips with my 08 Bullitt mustang. has supercharged 4.6 3V motor that makes 650 rwhp on pump 93 octane gas W/ 6 speed tr6060 trans.
i get about 18 around town with normal driving.
when i drive it like a rental car it's about 3-5 mpg. this is a guess because i never had calculated it.
