Going tonight to pick my son up from college. Driving through the night to get him. Its about 670 miles one way. Trying to figure out how mnay tanks itll take lol. Looked at manual, says about 21gal tank. But on my local driving fill ups I dont think I got above 16gals lol. Of course I has between 1/4 and E sooooo....Hoping to hit close to 17 mpg on highway lmao. Will see.