tucson: First, why don't you know what kind of gas mileage you get from your vehicle? Second, we are not mind readers. Might help us just a teensy bit to know what kind of vehicle you drive. Third, what route will you be taking? Failed to mention that in your failed attempt at a question. Fourth, are you aware of FREE mapping programs such as MapQuest, Google Maps, and Yahoo Maps? If yes, then at least you could tell us how many miles you will be covering during your trip. So, I will make up an answer. 16 mpg and trip will cover 830 miles at an average of $3.60 a gallon. You will need about $190 to cover the cost of gas. I would have $225 available just in case.|||Depends on your route length in miles, travelling conditions, type of vehicle you drive and it's running condition, and of course, gas prices|||about an arm, a leg, and a left nut nowadays.