Spare Tire PSI: What is Proper Inspection and Maintenance?

Spare tire PSI is necessary information that helps you to maintain standard air pressure in your spare tire. Thus, you don’t have to worry about tire failure while driving.

What is The Proper Control of Tire PSI

This guide discusses how to check the pressure of a spare tire and maintain it properly.

What Is the Standard Air Pressure for Spare Tires?

The standard air pressure for spare tires is 60 pounds per square inch (PSI). However, this is the recommended pressure for smaller tires. Smaller tires are only fit for emergency use, and they are expected to move at a maximum speed of 55 miles per hour.

Nevertheless, if you are driving a heavier vehicle, such as a truck or SUV, then you will need to use a full-sized spare tire. The pressure required for this type of tire usually ranges from 32 to 38 pounds per square inch (PSI). To be safe, it’s best you consult the owner’s manual to determine the right pressure for your tires.

How Can You Check the Air Pressure for a Spare Tire?

You can check the air pressure for a spare tire by using a pressure gauge. To perform this operation, first, remove the valve cap from the spare. Then place the pressure gauge on the valve stem. Press the gauge hard on the valve stem until the hissing sound disappears.

Tire Changing With Spare Tire

This will result in a reading on the gauge. If you are using a standard gauge, the pressure will push a small bar from the bottom of the gauge. When you observe the instrument, you will discover that the measurement units are inscribed into the bar.

If you are using a digital gauge, you will see the reading on the screen. The next step is to write down the reading. If you have more than one spare, repeat the same process.

Furthermore, before starting this process, check the manufacturer’s recommended PSI for the spare. This can be done by looking at the owner’s manual or the driver’s side door jamb. This information will help you evaluate if the pressure is at the recommended level.

How Should You Properly Inspect and Maintain Spare Tires?

You should properly inspect and maintain spare tires by checking the tire’s pressure and tire rotation. Other possible methods for inspecting and maintaining the tires include checking tread depth, tire condition, and age. Cleaning the tire is another effective method of preserving a temporary spare tire.

Check Tire Tread Depth

A tire’s tread depth is the vertical measurement between the tread rubber’s top and the bottom of the tire’s deepest grooves. You can evaluate the tread depth of the spare tire by using the penny test. In the tread, place a penny uPSIde down. If you can see the top of Lincoln’s head, it’s time to get yourself a new tire.

Mechanic Checking The Tread Depth

Another method that can be used is the tire tread wear bar indicator test. Examine the tread wear indicator bar that is etched into most cars. The bars are usually located at the base of the tread grooves in several places around the tire. If these bars become visibly flush with the adjacent ribs, the tread depth is less than 2/32 inches.

A tread depth that is below 1.6 millimeters or 2/32 inches lacks grip, and this will affect braking distance and vehicle control while driving. The lack of traction on the tire is your cue to replace it with a new one.

Check Tire Condition and Age

Inspecting the tire’s condition helps you ascertain its health. Ensure you regularly check the tire for signs of damage or any condition that may lead to replacement. The inspection should be done by examining the tread and sidewalls for any cuts, punctures, scrapes, bulges, bumps, or cracks.

Once you spot anything that looks out of place, contact a tire professional to inspect the tire and possibly diagnose the fault properly.

Furthermore, ensure that you keep track of the tire’s age. Although the tire’s tread may last for years without being worn out, this doesn’t mean the tires shouldn’t be replaced. So, it’s recommended that you use the spare tire no longer than ten years after its date of manufacture.

You can easily check the tire’s age by looking at the DOT stamping on the side wall. You will notice a 4-digit number at the end of the DOT stamping. This number is the date code, and it is easy to interpret.

The first two numbers are the week of manufacture, while the last two are the year. For instance, 2823 can be interpreted as the tire manufactured on the 28th week of 2023.

Inspect Tire Pressure

In simple terms, tire pressure is the amount of air inside the tire. It can be evaluated using a spare tire pressure gauge. Using the pressure gauge, you can confirm whether the spare tire has sufficient air. If it doesn’t, you must inflate it properly to fill the required air.

Checking The Pressure Of Tire

Also, the reading obtained from the gauge after measuring the pressure should be cross-checked with the vehicle’s recommended tire pressure. If the reading tallies with the manufacturer’s recommended PSI, the tire is filled with the correct amount of air.

Furthermore, the tires should be inspected while they are still cold. This is usually after they have sat idle for at least three hours or before you have driven one mile at a moderate speed. Lastly, don’t make the mistake of bleeding pressure from a hot tire.

Rotate the Tires

Tire rotation refers to the periodic changing of the position of each tire in a vehicle. The rotation of tires in your vehicle should be based on the manufacturer’s recommendation or for every 5,000 miles. However, for full-size spare tires such as trucks and SUVs, the tire should be rotated every 6,000 – 8,000 miles.

The spare tire is expected to be rotated into the correct rear position while the former rear tire becomes the new spare. For many car owners, you can habitually rotate the tires whenever you change the vehicle’s oil at the mechanic’s shop.

The tire rotation ensures even tire wear. By preventing the tires from experiencing uneven wear, you help increase the useful life of the tires. In addition, even tire wear helps you enjoy a smoother and safer vehicle ride.

Clean and Preserve the Tires

The cleaning operation is an effective way to keep a tire in good condition. This maintenance tip not only keeps the tire in a healthy shape but also helps you check for irregularities, cracks, and leaks on the tire surface. To perform this operation, you will need a quality protectant with UV protection that will enhance the lifespan of the rubber and prevent cracks or leaks.

Cleaning The Tire With Sponge

Another method is to use specialized cleaners to remove stains from the tire. If you have the spare mounted beneath the vehicle, ensure you use hard tire covers to protect the tire from debris or rock. The hard tire covers are usually made from steel plates, or you could use plastic covers instead.

How Often Should You Check the Air Pressure in Your Spare Tire?

You should check the air pressure in your spare tire at least once a month. In addition, the air pressure should be checked every time you rotate your tires, which should be every 6,000-8,000 miles. Thus, when you check your vehicle’s four tires, don’t leave the spare behind.

Ensure that you inspect its pressure alongside the other tires. If it is under-inflated, it should be filled with the required pressure to avoid a flat tire.

What Are the Dangers of Driving With an Under or Over-Inflated Tire?

The dangers of driving with an under or over-inflated tire are low ground clearance, the risk of losing control while driving, and a flat tire. Other possible dangers include easily damaged tires, the risk of a blowout or explosion, and excess ground contact.

Low Ground Clearance

Ground clearance is the distance between the lowest point of the car component and the ground. It is the least distance between the lower end of a car’s body or chassis and the road. It helps maintain the stability and quality of a vehicle. The higher the ground clearance or contact of a vehicle, the safer it is.

Driving an under-inflated tire can lead to low ground clearance in a car. This low ground clearance has detrimental effects, such as water entering the engine, difficulty passing uneven roads, and poor car suspension. If the ground clearance remains low for a long time, it will cause damage to the bottom of the vehicle.

Furthermore, the comfort of the passengers will be affected during the ride. Also, there is a possibility of an accident occurring while driving a car with low-ground contact.

Risk of Damaged Tires

Tires are responsible for a vehicle’s movement on the road. However, the tires need to have the right air pressure, or else they become damaged. If your vehicle’s tires are under-inflated, they won’t be able to maintain their shape. If this occurrence persists, the tires become flatter than they should be while in contact with the road.

Damaged Flat Tire

Under-inflated tires can deteriorate into tire failure and cause the tire’s tread life to reduce drastically by as much as 25 percent. At this point, the damaged tires can lead to an accident while driving. In addition, the reduced pressure in the tire will make it bend more whenever it rolls, and this will cause internal heat to build up.

The buildup of internal heat will lead to an increase in rolling resistance and reduced fuel efficiency. Thus, there will be a considerable loss of steering precision and cornering stability when driving on such tires.

Risk of a Blowout and Losing Control

When the tires become damaged, they may explode or blow out unexpectedly. This explosion or blowout can cause the driver to lose control of the vehicle. If the driver cannot regain physical control of the vehicle immediately, it can lead to an accident.

When a driver loses control, the vehicle may skid, swerve, spin, or roll over. Whichever of this occurs, one thing is certain – the vehicle will most likely be involved in an accident. Accidents due to loss of control could be single-vehicle crashes or involve multiple vehicles.

To avoid this problem, ensure that the tire is properly inflated. It shouldn’t be less or more than recommended. The correct amount of air pressure should be pumped into the tires.

Excess Ground Clearance

Over-inflation of tires can cause excess ground clearance. If your tire has a higher PSI than the recommended level, it can lead to high ground clearance.

A Tire With Standard Pressure

If the ground clearance of your vehicle is too high, it can have some negative effects. Disadvantages of excess ground clearance include increased rollover risk, reduced stability and handling of the vehicle, reduced fuel efficiency due to increased wind resistance, and difficulty in entry and exit.

Frequently Asked Questions

Should You Air Your Tires to the Maximum PSI?

No, you shouldn’t air your tires to the maximum PSI because it can be detrimental. The tires will be affected by heat and cold weather, which can lead them to failure. You should ensure the PSI is a few pounds below the max level.

What Is the PSI at Which Tires Explode?

The PSI at which tires explode is over 200 PSI. Tires explode when you overinflate it beyond the recommended manufacturer’s level. For a full-sized tire, it should be pressurized to 30-40 PSI. The explosion can cause serious injury or loss of control while driving.


Having read this article, you now know the standard air pressure for tires and how to check the pressure of your tires. Here are concluding thoughts on the main points and frequently asked questions discussed:

  • You can properly inspect and maintain spare wheels by checking the tire’s pressure. You should also check the rotation, tread, condition, and age of the tires.
  • The dangers of driving with an under or over-inflated spare tire are low ground clearance, risk of losing control, easily damaged tires, risk of a blowout, excess ground contact, and less physical control while driving.
  • You shouldn’t air your tires to max PSI because it can be detrimental. It is advised not to go for the upper limit of your tires’ PSI because they will be affected by heat and cold weather, which can cause tire failure.

With the knowledge gained in this guide, it should be easy for you to inspect and properly maintain your vehicle’s extra tires.

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