$7,000 more this year?? Gas is on average .50 higher than last year, which means you purchase 14,000 gallons/year? (for the math impaired, 14,000 gallons times .50 extra/gallon = $7,000). So your combined household miles driven in a year = 250,000 miles? Say 250,000 miles, divided by 18 mpg = 13,889 gallons of gas purchased @ .50 increase ~= $7,000. So you have 10 cars driving 25k per year? 5 cars driving 50k per year? 3 cars driving 83k miles per year? Wow, impressive! Assuming an average 15mpg, you'd still be driving 210,000 miles per year...