My thoughts is gas in the tank is always better than gas in a can. One, its a lower center of gravity. But two, and most importantly, you don't have to "donate" it to a gas guzzling Heep, because they thought they could get out to Chicken Corners and back to City Market on 3/4's tank of gas, only to get the can handed back to you COMPLETELY empty and a "Thanks, man" for repayment.
been there, got the bumper sticker "I drive a Jeep, therefore I have a small brain and a smaller penis."