Im only getting 15-18 mpg city and 22-24 mpg highway. I have new bosh plugs, new air filter, new oil and filter, and im getting ready to do a trans fluid change.

I have 430k miles on theorigional motor and trans. Im just thinking of possible solutions. If i were to change motors it would be to a smaller v8 or a decent size v6. unless i can find ways to increase my mpg with the current motor.