Drive the speed limit. You will get better gas mileage if you slow down, rather than speed. Each 5 mph over 60 mph lowers your gas mileage by 2.5 mpg. This may sound insignificant, but depending on how much you drive, you could save lots of money. Going 80 mph rather than 60 mph could cost you more than $900 per year.
Besides, going 80 mph is probably illegal where you live anyway. You could save the money in paying a traffic citation if you keep your car below 60 mph.
