It’s summer road-trip season. AAA estimates that a record-breaking 44.2 million Americans will travel 50 miles or more during the July 4 holiday weekend. Before you hit the road, follow these simple tire-maintenance tips to keep your plans from going flat. 

Heat Is the Enemy

Tires can overheat from being underinflated, overloaded, or pushed at higher speeds. Factor in hot summer temperatures and sizzling road surfaces, and there’s a chance a tire could overheat and blow out.

Make sure your tires are properly inflated. Only about 19 percent of consumers properly inflate their tires, according to government estimates. A simple inspection can improve your safety:

  • Check pressure when the tires are at same temperature as their surroundings, typically after they’ve been parked for more than 3 hours.
  • Set the pressure to the prescribed level, which can be found on a placard on the driver’s doorjamb in most cars. Don’t use the pressure that’s noted on the tire’s sidewall; that’s the maximum pressure allowed for the tire. (See our tire pressure gauge ratings.)

Check out CR's additional tire and maintenance advice.

Don’t Overload

A common practice to judge cargo capability is to see what fits. That’s not the wisest approach. This can lead to overloading the vehicle and tires. Refer to the tire information placard, which provides the allowable weight of all occupants and cargo combined. You might be surprised to learn that many vehicles are considered loaded to capacity with just a few adults, without anything in the trunk or cargo area.  

Check the Spare Tire

It’s often overlooked, but you should check your spare tire every time you check the inflation pressure of the other tires on your car. (That should be done monthly and before long-distance trips.)

Of course, many modern vehicles don’t carry spares. Some models have run-flat tires, which retain enough sidewall stiffness after being punctured to make it to a service station or tire shop for replacement. Also, it’s increasingly common for new cars to come with a tire-inflation or sealant kit that can be used temporarily fix a punctured tire. These may sound like a fair trade-off for a spare, but they can only repair and re-inflate tires with simple holes through the tread. A tear in a sidewall means a replacement tire needs to be brought to the car or the car needs to be towed or taken by a flatbed to a repair facility.

Ultimately, run-flat tires and repair kits are not as good as having a spare. Be sure to know your options and limitations before heading out on the road, especially when traveling through areas where help may be far away and cell service may be limited.

Enough Tread to Travel

In addition to hot, sunny weather, be ready for the common thunderstorm deluge. Worn tires have reduced wet grip and are prone to hydroplaning. Make sure you inspect the treads. Tires are worn out when they reach a tread depth of about 2/32 inch. That’s the point where tread depth is about as deep as the distance from the top of Lincoln’s head on a penny to the edge of the coin. You can also look for treadwear bars at the bottom of major grooves that will appear flush with the groove to indicate the tire is worn out. Ideally, you should be shopping for replacements by the time the tread measures 4/32 inch, or the depth to the top of George Washington’s head on a quarter.  

Beware Gators

Watch out for "gators" on the Interstate—long strips of damaged tire tread that come from failed big-rig tires. In hot weather, there are more frequent sightings of these. Gators can be a few feet long and weigh several pounds. Striking one can damage your car, and any debris you kick up could pose a danger to the cars behind you. 

Tips for the Perfect Road Trip

A road trip is one of life's great adventures. On the "Consumer 101" show, host Jack Rico learns from Consumer Reports expert Mike Monticello how to prepare for a safe one.