Air resistance or drag is the atmosphere resisting forward movement. If you’ve ever held your arm out of a car window, you’ve felt that resistance. And you know how much more powerful it is the faster you go. That same force is at work against your car, meaning the faster you go, the higher the drag coefficient.
Modern cars are slightly more aerodynamic than their 1970s counterparts, so 60-65 mph might be the new 55. Because there are so many different models of cars, there isn’t a one-size-fits-all answer. Smaller cars save more fuel at higher speeds than heavier cars. But for most cars, the sweet spot for fuel economy is between 40 and 60 miles per hour. Don’t forget to keep your vehicle’s service up to date. CLICK HERE