Hey, nice to meet you. If it is any consolation is higher trap speeds with aero modding. I were you, sell the Mazda, work the truck (or use some $ to buy tall skinny tires and skidplate if you need it for off road).I think you have decent aero with the truck. Another option, also sell the tired F150 ,get a diesel truck and start with a much better platform. There are lots of rad ways to do up a truck for mpg. Also, weight reduction is cool. You can also sell stuff
Edit: reread that, and reread your post. Since you are enjoying the challenge in the Mazda you should probably keep it.