Les Schwab Tech Tip: Quick Guide to Properly Inflated Tires

Having the right air pressure in your tires is vital. After all, it’s the air in your tires that supports the weight of your vehicle, not the tires themselves. Underinflation or over-inflation can damage your tires and wear them out faster. Plus, the wrong PSI (Pounds Per Square Inch) can affect fuel efficiency and stopping distance. Here’s a quick guide to understanding tire pressure, and where to find the recommended tire inflation pressure for your vehicle.


Where to Find Your Recommended PSI

Remember your first real bike? On the side of each tire was a recommended PSI. That’s the number you used when inflating the tires. That’s not exactly how PSI works on your car or truck. The recommended tire pressure for your vehicle is located in your owner’s manual or on the driver’s side door sticker. In some cases, it will list the PSI for both the front and back tires when cold for the original equipment or equivalent tires. (For example, first thing in the morning before the vehicle has been driven.) You may find the PSI for your spare as well.

Les Schwab Tip: Deviating from the original tire size that came with your vehicle can affect the recommended PSI. If you have questions, stop by your local Les Schwab.

What does the cold PSI on the side of your tire indicate? That is the maximum pressure the tire is designed to safely hold, which may be different from your vehicle’s recommended tire pressure.

Vehicle door placard showing front, rear and spare tire cold tire pressure.

As of September 1, 2007, all light motor vehicles (cars and trucks with a gross vehicle weight rating under ten thousand pounds) were mandated to come equipped with a Tire Pressure Monitoring System (TPMS). Most of these vehicles are equipped with a system that will alert you when one or more tires aren’t properly inflated. For more information, please see our Guide to Tire Pressure Monitoring Systems.


Check Your Tire Pressure Monthly

Your tire pressure will fluctuate as you drive. Weather, elevation, and how the vehicle is being driven can all be factors. Therefore, the best time to check and inflate your tires is in the morning, before you’ve traveled more than a few miles.

On average, tires will lose one pound of pressure per month. Plus, summer and winter months can play havoc with your tire’s recommended tire pressure. Summertime heat can increase the PSI while cold weather can lower it. You can see why monthly checks are a good idea.

Anytime you’re out and about, pull into your local Les Schwab. We’ll check your tire’s air pressure for free and get all of your tires to their proper inflation.

For more information, please check out our article How to Make Your Tires Last Longer.

Save Money

Tires inflated to the correct air pressure will improve fuel efficiency year-round. When your tires are under-inflated, your car works harder to move forward. Just 10 PSI lower than recommended can reduce your MPG by up to 2 percent, according to a National Highway Traffic Safety Administration (NHTSA) report.

Improve Safety

A crash causation survey done by the NHTSA found that improper tire inflation is, in part, the cause for 9% of crashes. When a tire is under or over-inflated, it can affect the handling, stopping, and impact crash-avoidance systems in some of today’s new vehicles.

What About Towing?

Some truck and other vehicle manufacturers recommend higher tire pressure when a truck is loaded down or towing a trailer. It’s always a good idea to stop by your local Les Schwab before over-inflating your tires when towing anything. See Trailer and Tire Do’s and Don’ts for answers to some common questions.


Les Schwab Knows Your PSI

Pull into your local Les Schwab and we’ll check your tire pressure, add air when needed to achieve the recommended tire pressure, and help you get safely back on the road.