How Much Tire Pressure Is Too Much?

Tire pressure is one of the most valuable aspects of a vehicle that you should always keep in check to avoid accidents. If the tire pressure isn’t right, it can damage the tires or cause tires to wear out over time.

But how much tire pressure is too much? Well, it depends on a few factors. 

In general, above 40 psi is considered to be over-inflated and below 32 psi is under-inflated. 

So, want to know more about the ins and outs of tire pressure and the factors involved? If yes, then binge on reading till the end.

The Temperature Factor

The thing about tire pressure is it can vary as a result of temperature. If it’s 75 degrees and you fill your tires at that time, the tire pressure decreases when the temperature drops at night.

Moreover, the air volume within the tires increases with the increasing temperature, and thus the tire pressure also increases. Generally, the temperature drops at night, which makes the tire pressure drop too. 

Tire pressure is measured in pound-force per square inch (psi). Every 10 degrees of change in the temperature causes tire pressure to increase or decrease by 1 psi. 

Here’s a basic calculation, if you inflate your tires to 32 psi when it’s 70 degrees in the daytime, as the night approaches and the temperature drops down to 20 degrees, the pressure in your tires will be 27 psi, which is too low.

Tire pressure should always be kept in check to maintain a safe journey. There are systems to keep your tire pressure in check that lets you know when it’s getting out of hand called TPMS. 

Problems Due to Incorrect Pressure

You could face several difficulties while driving if you don’t have the optimal pressure in your tires. The proper reading of tire pressure is the cold inflation pressure.

The tire pressure also varies when the vehicle is started. After you’ve driven for a while, all the friction of the tire with the road causes the tires to warm up and the tire pressure to vary. 

So, it won’t be accurate to measure tire pressure when the tire is heated!

Cold inflation pressure is the pressure that is measured from the tires when the vehicle is yet to be driven and when the tires are not heated. 

Then again, there are two terminologies: under-inflation and over-inflation, that you need to know

Under Inflation

Low tire pressure or under-inflation can cause various problems to the vehicle. 

The most significant drawback is your car loses stability. Additionally, it makes it considerably harder to retain control in adverse weather.

Moreover, under-inflated tires won’t allow you to make hard emergency turns or brakes, which can sometimes prove fatal. Another problem with underinflation is it wears out the tires more quickly.

Note − Even a 5 psi fall in the tire pressure can cause tire failure. Additionally, you can lose cornering stability and steering accuracy.

Over Inflation

Excessive tire pressure or over-inflation provides you with a rough ride. However, handling the car becomes easier in bad road conditions.

When your tires are over-inflated, they don’t cover the intended area on the road. 

Increased tire pressure often improves cornering and steering action. But as you’re not on a racing track, you shouldn’t keep the tires over-inflated!

The significant problem with over-inflation is the tires get damaged easily. 

If the pressure is high, the area of the tire increase and the small unnoticeable particles on the road cause more damage to the over-inflated tires. 

Even if you have an overinflated tire by 5 psi, it could cause a sudden blowout and, as a result, incur an accident.

The Optimal Pressure for Your Tires

The optimal tire pressure can vary depending on the vehicle type and load. 

Larger and heavier vehicles must have greater tire pressures. Vehicles that carry heavy loads need higher tire pressure in the rear wheels. 

However, the recommended tire pressure for passenger cars is 32 – 40 psi. To go over the 40-psi range wouldn’t be wise. But in the case of trucks or lorries, 40 psi is kind of low. 

On the other hand, with smaller cars, even 40 psi can be too much. In a nutshell, more than 40 psi for a medium-sized vehicle is not recommended. 

Experts’ Note: Every car has a recommended tire pressure by the manufacturer. Before filling air into the tires, you must check the recommended tire pressure, usually found on a sticker on the driver’s door. 

A Little Higher Pressure Is Better Than Lower Pressure

Lower tire pressure can almost always be a risk than high tire pressure when tires are under-inflated. And more rubber contacts the ground surface, which causes the tires to get heated up and increase the risk of a blowout. 

When the tire pressure is low, the ride becomes soft and comfortable. But it also increases the risk factors. 

Moreover, tire pressure also plays a very important role in fuel economy.  

Again, a little high tire pressure gives you a little bumpy and rough ride, but the risk factors are lower. Moreover, the fuel economy is better if the tire pressure is higher. 

If you use overinflated tires by 2 psi, you can get better handling and mileage, but it comes with the cost of your comfort. Although the ride will be a little bumpy, it doesn’t harm the tires that much and is affordable.

Even if you have overinflated tires by 3 psi, it shouldn’t make that much of a difference. But it’s always recommended to maintain the optimal tire pressure.

Tire Pressure Monitoring System

Nowadays, almost all cars have a TPMS (Tire Pressure Monitoring System). It is an indicator of when your tires lose the optimal pressure. 

The indicator even warns you about the tire condition via a pictogram display, gauge, or simply a warning light. 

In the end, it’s a device that can also get faulty or display false results. So, it’s always recommended that you check on the tire pressure once in a while to avoid any possible mishaps. 

The Bottom Line

So, we believe you now know how much tire pressure is too much for your type of vehicle. Excessive or low tire pressure can damage the tires for good, and getting brand-new tires can prove costly. 

Keeping this in mind and with the fuel cost, maintaining optimal tire pressure becomes an economic decision. 

Going over 40 psi is not recommended if you have a medium-sized vehicle. This could impair the tires over time and cause them to wear out quickly.