200 miles. Just like a 5.7 V8!Around town, racing back and forth to the hospital for emergencies, I get 13-15mpg, and have to fill up about 200-225miles. The additional potential of quiet highway driving takes it to nearly 400 miles. (And the math confirms that: 18gal x 13mpg =234. 18 x 22 = 396). I usually fill up before I run the 20 gallon tank completely dry.