Tire Thumping: Why Do Truckers Hit Their Tires?

An argument could easily be made that the bulk of the general public is simply not cut out to work as a long haul truck. Spending hours upon hours cruising the open road all alone would likely be the first of many deal breakers for most people eyeing a potential career as a trucker. Safety would almost certainly be a close second, as logging so many freeway miles does indeed come with certain perils. There are, of course, measures that truckers can take to help ensure their semi is ready to tackle whatever may come on the road ahead, and tire thumping is on the safety checklist of any trucker worth their salt.

Even if you've never heard that term, it's entirely possible you've seen a trucker do it on those occasions you've pulled into a freeway rest stop for fuel and food. Indeed, tire thumping is exactly what its name implies and involves walking around a vehicle to strike each tire with some sort of bat, rod, or hammer.

This can take a few minutes, since vehicles from most popular semi truck manufacturers use as many as 18 tires — hence the term "18 wheeler" — and watching a trucker thump each of their vehicle's tires before they get on the road will be a peculiar sight for some. But it's also a vital safety precaution, as thumping is an easy way to check a tire's air pressure.

Checking the air pressure of a semi truck's tires is incredibly important, as low pressure ranks among the biggest factors in the failure of a tire. Such a failure in a semi could be dangerous to not only the vehicle's operator, but also to any other drivers on the road. Checking pressure on a semi is also trickier than on normal vehicles, as their massive tires can often look inflated even when the air is low.

Tire thumping has become common practice for truckers in large part because it doesn't require a ton of time and effort. While Amazon currently sells a number of devices made specifically for tire thumping, they are also not a necessity, as many objects — including a common hammer — can be used to perform the task. That said, when properly executed, tire thumping can be very telling as to the state of a tire's air pressure.

At its core, the methodology of tire thumping is quite simple, as all you need to do is firmly strike the tire on the tread or sidewall. As you do so, the first thing you should pay attention to is whether the thumper bounces back quickly. If it does, the pressure should be ok. If not, the air pressure may be low. The other tell is the sound the tire makes when it is struck. Specifically, you want to ensure the tires all make the same sound when you strike them. If one sounds different, you'll want to check it closer before you get on the road.

Apart from general safety, it should be noted that ensuring a vehicle's tires are all properly inflated to the same PSI (pounds per square inch) can also help with fuel economy, which is a particularly big deal in the trucking world. And yes, you can actually use the tire thumping method on your everyday vehicle if you're so inclined. But while the method can be useful for any driver, it's just the first round of defense when it comes to ensuring the tires on a vehicle are all properly inflated.

Of course, these days many consumer vehicles come equipped with tire pressure monitoring systems that alert drivers whenever a tire is low. Many newer semi trucks also boast this feature, though the sensors may not be gauging the tires affixed to the trailer they're pulling. Whatever the case, if you see an alert triggered by one of those sensors, you'll need to tend to the problem tire(s) as soon as possible.

As for the tires that may not have air pressure monitoring systems charting their levels, if you come across a tire that sounds or feels off during your next thump, the most efficient and precise way to check its pressure is to utilize a tire pressure gauge. When a gauge is used the correct way, a tire pressure gauge will help you determine not only how low or high the pressure is, but also tell you exactly how much air you need to add or remove to achieve the correct PSI for your tire. As such, it's about as invaluable a tool as one can keep stowed away in a vehicle, be it a passenger car or an 18 wheeler.