i just need something that i can get better than 250 miles on a highway off 14.5 gallons of gas because i cant do it right now in the Tib

I would like SUV/Truck but at 19 or 20 mpg on the highway its just not a good idea plus SUV/Trucks run around 20k miles for around $20k but an SRT4 with 8K miles i can get for $18K soooo