You are probably aware that driving with under-inflated tires will negatively impact your car’s gas mileage. Since under-inflated tires cause drag, they ultimately require more horsepower. The end result is that the car uses more gas per mile.
What about over inflating your tires? Conventional wisdom seems to suggest that if under-inflated tires reduce gas mileage, over-inflated tires should improve it. Is there any truth behind this thinking?
Debunking the Myth
The logic behind the myth actually makes sense. Over inflating your tires means that they will bulge slightly in the center. Less surface area making contact with the road should mean less rolling resistance. With decreased rolling resistance and friction, your car’s gas mileage should respond in a positive way, right?
The answer is slightly more complex than you would expect. The truth is that your car was built with aerodynamics in mind. This basically means that at highway speeds, your vehicle is already near its maximum fuel economy. Any small changes you make to your tires will be virtually undetectable.
Yes, over inflating your tires can decrease your car’s rolling resistance. However, it will probably not provide you with the monumental gas saving results you were hoping for. In fact, over inflating your car’s tires can actually be dangerous. When tires are over inflated, the steering becomes compromised and limited. The end result being that you are more prone to end up in an accident.
The best gas saving and safety advice is to follow the manufacturer’s recommended tire pressure. Get in the habit of regularly checking the PSI of your tires. With the proper maintenance, you can ensure that your vehicle continues to run at its optimal performance.