During a pre-trip inspection, you should check tire pressure and tread depth.

Tires are your contact with the road, the only thing standing between your rig and reality out there. On a long haul, that connection matters more than you might think. A quick, deliberate pre-trip check isn’t just a box to tick; it’s the difference between a smooth ride and trouble on the shoulder, or worse. So, what should you focus on when you inspect your tires? The answer is simple, but powerful: check the tire pressure and tread depth.

Let me explain why those two things matter more than any color, brand, or the tire’s age sitting in the cabinet.

Why tire pressure is a big deal

• It’s about safety and control. When tires run underinflated, they flex more, which means they heat up faster. Heat is the enemy of rubber, and over time it can cause heat-induced wear, sidewall damage, and, in a worst-case scenario, a blowout. Overinflation isn’t a harmless exaggeration either. It can make the ride feel jittery, lead to uneven wear, and reduce traction by making the tire’s contact patch smaller.

• It helps with fuel efficiency and braking. Correct pressure equals better fuel economy and more predictable braking performance. Think of it as keeping the tires honest so your fuel stops aren’t wasted and your stopping distances aren’t exaggerated by a squeaky wheel deal.

• It’s not just the front tires. In a heavy-duty setup, you’ve got a front axle and a bunch of duals behind it. Each tire needs the right air, because underinflation on even one tire can upset handling, especially in curves or when you’re braking hard.

• How to check it sensibly. Do the check when tires are cold (before you’ve rolled a mile or two). Use a reliable tire pressure gauge, either a dial or digital one. Read the value from the door jamb sticker on the truck or the owner’s manual if you’re unsure where the recommended pressure sits. If you’re like a lot of drivers, you’ll keep a small gauge in the cab so you don’t forget to check. And if you’re running a long haul through shifting weather, you’ll want to recheck after loading, since steady weight can shift the pressure a bit.

• Quick tip you’ll thank yourself for later. Treat the tires as a system, not independent parts. Check all tires, including the spare, and don’t forget the valve stems and caps. A loose or missing cap can let air escape slowly, and the stem can crack with age. It’s a small thing that saves big headaches.

Tread depth: your grip on the road

• Traction is everything, especially in wet or slick conditions. Tread depth is the shape of your grip. Worn tread loses its bite, and slick patches can turn a routine corner into a scare. Hydroplaning is real, and it doesn’t care how careful you were yesterday.

• How deep is deep enough? States and jurisdictions set minimums, and those rules are there because they keep you safer. A good rule of thumb for many trucks is that you want more than a bare minimum, especially on steering tires. In practice, using a proper tread depth gauge gives you a clear read; the penny test or the coin test is a quick, rough gauge if you don’t have a gauge handy. With the penny test, if the top of Lincoln’s head isn’t visible in the tread groove, you’re likely above the emergency line. If you can see Lincoln’s entire head, you’re past the safe limit. A gauge is better for accuracy, especially on multiple axles where you want consistent readings.

• Front-to-back and pair considerations. The front tires often take the brunt of steering and braking forces. If your steer tires are worn more than your drive tires, you’ll feel it in the steering and in stopping distance. That’s not just a math problem; it’s a safety issue you’ll notice in rain, snow, or a slick ramp.

• What about the age of tires? Yes, age matters. It’s not a magic number; rubber can degrade even if tread looks decent. But age alone doesn’t tell the whole story. A tire can be fairly young but cracked, dry, or damaged from road hazards. That’s why the check isn’t just about the number on the sidewall; you want to inspect for cuts, bulges, or sidewall damage, which can hide a weak spot that could fail on you.

Beyond pressure and tread: a few quick checks to round out the picture

• Look for visible damage. Any cuts, bulges, or sidewall cracking deserves attention. It doesn’t matter if the tread looks good—if the sidewall shows damage, you’re inviting a failure at the worst moment.

• Check for even wear. Uneven wear can signal alignment issues, improper inflation in parts of the tire, or suspension quirks. If you notice one tire wearing out faster, don’t ignore it—gaps in wear pattern can be a clue to a bigger problem.

• Valve stems and caps matter. A missing cap isn’t glamorous, but it’s a line of defense against dirt and moisture that can corrode the valve. A damaged stem is a sneaky culprit for slow leaks.

• Don’t forget the spare. The spare matters too. It’s easy to forget about it until you need it, and then you wish you had checked earlier. The spare should be ready to go—properly inflated and in good condition—so you’re not caught flat-footed.

A simple, dependable pre-trip rhythm you can live with

Here’s a way to make tire checks second nature, without feeling like you’re performing some magic ritual.

• Start with the basics. Check all tire pressures first, then move to tread depth. Do this on a cold morning or after you’ve parked for a while. Make note of any pressure differences between tires, especially if you’re dealing with duals.

• Inspect the tread with purpose. Use a gauge for accuracy, but keep a quick visual check in your routine. Look for consistent wear across the tread. If something looks off, pull into a safe spot and measure it.

• Scan for signs of trouble. Look for cuts, bulges, cracks, or foreign objects lodged in the tread. If you find something suspicious, don’t drive on it—address it.

• Check the hardware. Lug nuts should be snug and secure. If you hear a rattle or feel a wobble, inspect the wheel assembly as part of your tire check.

• Do a final walk-around. A thorough pre-trip isn’t just about one system. Take a few extra minutes to look at the mirrors, lights, and load securement. A good eye for the overall rig reduces surprises.

Sometimes a quick tangent helps keep the focus, and that’s okay

While we’re on the subject, a few related notes pop up all the time in the field. For instance, you might wonder why some drivers mention tire pressure numbers in terms of “cold” versus “hot.” It’s simple: tires heat up when you drive, so the pressure rises as the tire warms. Reading pressure after a trip or after you’ve driven can give you a falsely high reading. That’s why the cold check—before you roll—is the most reliable.

Or consider the question of matching tires. Yes, uniform tires across the axle are a sensible idea for load distribution and handling. But on the road, you’ll meet all sorts of configurations. The key is to know your own vehicle’s specifications and follow the manufacturer’s advice, while keeping a close eye on safety signs and wear patterns. It’s not a fashion show of tires; it’s about consistency, safety, and predictability when you need it most.

A few practical takeaways you can apply today

• Keep a tire kit inside the cab with a reliable gauge, a small flashlight, and a portable air compressor if you’ve got one. It’s a small setup that pays off when you’re late to a delivery and the pressure light starts talking.

• Make pressure checks part of your pre-trip routine, not an afterthought. Treat it like checking the oil level or the fuel gauge—essential, quick, repeatable.

• Use a tread depth gauge for accuracy, and carry a spare measuring tool so you’re never guessing.

• Remember: the safest ride comes from a balanced approach. Pressure, tread depth, and a quick visual scan together tell you more than you’d expect about how your tires will behave on the road.

To sum it up, what should you check on your tires during a pre-trip inspection? The tire pressure and the tread depth. It’s the combination that keeps you safe, helps you handle the road with confidence, and reduces the odds of a nasty surprise in bad weather. Color of the tread, tire age as a single factor, or whether tires match in size and brand—these are things to consider, but they don’t carry the same weight as keeping the air right and the grip solid.

If you’re wondering how this translates into real-world efficiency, think of it like maintaining a reliable bicycle—well-inflated tires and solid tread let you ride farther with less effort. And in trucking terms, that translates into smoother rides, shorter stopping distances, and fewer squeaks and squeals on the highway.

So next time you roll to a stop, take a moment with the tires. A couple of careful checks can save you from a lot of trouble down the line. It’s not just about passing a checklist; it’s about the confidence that comes from knowing your tires are ready for whatever the road throws your way. After all, you’ve got a load to carry, a schedule to keep, and a lot of miles ahead. The tires deserve your attention—because you deserve a safer drive.