Hello. I have a second generation dodge stratus and i get 18 mpg. The way i did it was i found
Record miles & gallons and fill up
Record miles & gallons at second trip and fill up
subtract the miles (find the difference)
divide by the gallons of the second trip

This got me 18. So i have 18 mpg and i think i should have well over 20. Any suggestions? (I really need some solutions to raise the mpg, so i waste less on gas!)

Thank You All!!!!!