One of the worst ways to waste gas when driving your car is to accelerate quickly when the red light turns green. When you make your foot act like a solid piece of lead, all you really gain in time savings is just a few seconds. Slowly accelerating and getting to the desired speed saves gas, and you will get to your destination in just about the same amount of time. Also, if you do pass a car, try to do it when going downhill, not up. The amount of gas burned trying to pass a car while going uphill is a major gas guzzler.