Guys! I'm at the pump right now and I've put about 12 gallons in, but I'm not sure how full I should fill it up to. How much do you usually put in? I don't want to top it off because the extra weight will reduce my mileage, but I'm tired of stopping for gas every 100 miles. What do I do? Should I get an aux tank so I can still keep the weight down but carry more gas?