It’s a bad idea to run your tire PSI way above your recommended range–and won’t actually help your MPG. This isn’t even a “more is more” scenarios where you want to aim for the top of your range. See, overinflating tires can make the tread on the surface of your tire to wear unevenly so they don’t last as long. They can also cause a stiff ride and suspension damage. But there are three even more deadly dangers to over-inflating your tires.

1- Sidewall blowouts

The first and most obvious risk of putting too much air in your tires is that they can pop under pressure. This is called a blowout and, when driving down the highway, it can be deadly. If you have a tire explode, especially one of the front ones, you’ll be working hard to keep control of the vehicle and come to a stop.

2- Reduced vehicle control

This second one is a bit more technical: as you increase a tire’s pressure and it gets stiffer, less of its tread surface touches the road. Less rubber on the road means less traction. Less traction means worse acceleration and worse braking. Essentially, it takes less force for your tires to “break lose” from the pavement and send you skidding down the road. But in one situation it’s even worse.

3- Risk of hydroplaning

Ever wonder what all those squiggly channels and grooves through the surface of your tire are for? They are carefully engineered to force water out from between your tire and the road. At high speeds your tires can surf across any water pooling on the raod. This phenomenon is called “hydroplaning” and the danger is that when you hit the brakes, your tires (and vehicle) just keep gliding. When your tires are overinflated, these channels can’t shed water properly and you risk hydroplaning at lower speeds.

Why would people over-inflate their tires? First and foremost, it might just be an honest mistake by you or your mechanic. Second, you might just think that if low psi is bad, more psi is always good. Finally, there is a myth that overfilling your tires improves mpg. And while it’s true that under-inflated tires reduce mpg, they are engineered for the highest mpg at the manufacture’s suggested range. Over-inflating doesn’t increase mpg. And now you know it puts you at risk in three big ways. So it’s never a bad idea to have a tire gauge and double-check them during your weekly vehicle inspection.