There is no need to tell motorists today that gas prices have gone through the roof and that gas mileage comparisons are important. Not only have prices risen steeply, they have done so in a relatively short time. And there seems little sign of relief. That is all the more reason to consider the miles per gallon or MPG information when buying your next car. You may even think about changing vehicles. There are alternatives with hybrid models and those very rare electric cars currently buzzing around some cities. But for most of us we need to know how efficient our car is in terms of gas.