My 2019 Mustang GT gets has averaged about 22 for mixed highway/city driving over 9K plus miles. Iy will run low 13s and might get 13 flat with slicks at my elevation (around 1,000 ft). I think the weight is around 3400 and it has a 10 speed auto. I can't see you doing much better than that. Even if gas is $4 and you drive 10K miles a year, the fuel cost difference between 30 and 20 mpg is only about $675 year. Pick your poison. Speed costs money in fuel.
Regards,
Kris
