I can't suggest a specific car but I want to say that it's good that you are concerned about gas mileage. Nothing spoils a good romp on the track more than poor MPGs.
Sorry to read that Joe.
Here are a few things that may be helpful to look at:
https://www.ldnscience.org/resources/interviews/interview-burton-berkson
https://thetruthaboutcancer.com/systemic-proteolytic-enzymes/