Five Things That Kill Your Gas Mileage

Here are five things that kill your gas mileage:

1. Speeding. As far as gas mileage goes, the best speed for most cars is 50 mph. And every 5 miles per hour over that costs you an extra 15 to 20 cents a gallon.

2. Driving aggressively. Gunning it and hitting the brakes constantly wastes more fuel, because it takes more gas to get your car moving than it does to keep it moving. And it can lower your fuel efficiency by up to 33% on the highway.

3. Flooring it when the light turns green. It's a lot better for your gas mileage if you speed up gradually.

4. Tailgating. In NASCAR it's called "drafting," and drivers do it to save fuel. But everyone's going different speeds on the highway. So you end up hitting the brakes a lot more, which kills your gas mileage.

5. Driving with a ton of crap in your car. Every extra 100 pounds decreases your gas mileage by about 1%.