Should I Fill My Tires To Max Psi? Why or Why Not?

For regular driving of the passenger car, you should not fill the tire to the max PSI. Your car’s tire will wear out faster than usual. You will experience more difficulty in handling and braking. However, you have to fill trailer tires, boat tires,s and RV tires, to their maximum PSI for proper efficiency. In the winter season and for towing purposes, you have to increase the pressure more than the recommended PSI. 

If you want to know the answer to “should I fill my tires to max PSI”, keep reading the article.

Should I Fill My Car Tires To Max Psi?

No, for the regular driving of your passenger car, you should not fill the tire to the maximum PSI listed on the tire’s sidewall. The same goes for bikes. Here are some reasons why it’s not ok to fill the tires to max PSI. 

Reason 1: Risk Of A Blowout

When the tire is filled to the maximum pressure, we can consider the tire to be over-inflated. In this case, while driving the car, the temperature inside the tire rises and causes the pressure to increase further. 

This process is called thermal expansion. Gradually the pressure increases to a level the tire can’t handle. It put too much strain on the tire walls, leading to a blowout. 

Blowouts while driving are very dangerous as the car can spin into other lanes causing a massive accident. This is why its always recommended to check tire pressure before driving.

Reason 2: Risk Of A Puncture

When the tire is filled to the maximum pressure, they become more rigid and less flexible. Their capability of absorbing the impacts from the road surface decreases, so, when they pass through sharp objects and debris from the road, the tire is most likely to get punctured. 

Reason 3: Unsafe Handling & Braking

When the tire is filled to the maximum PSI or is over-inflated, the center of the tire bulges outward. So, the tire gets a smaller contact patch with the road surface. 

Due to this reason, the tire can not grip the road as it should, resulting in the car being more likely to slip or lose control. Also, the braking distance of the car also increase that can result in accident in an emergency. 

Source: China Tires

Reason 4: Bumpy Ride

An overinflated tire wears out unevenly as only the middle part of the tired tread comes in contact with the road. Also, the excessive pressure causes the tire to be less flexible. This makes the ride feel rough and bumpy, and you feel the bumps on the road more strongly. 

For these reasons, you should always inflate your passenger car tires to the optimal or recommended level which is 32 PSI to 35 PSI. It may vary depending on your car’s type. 

However, in some situations and with some tire types, you may need to increase the PSI of the tire, even sometimes to the max. We will discuss those situations below. 

Should I Fill My Tires To Max PSI For Towing?

Yes, you can fill the tire to the maximum PSI while towing. For towing, lesser friction can be helpful. So, increasing the PSI will give you this advantage. But you should gradually increase the weight you are carrying.

For example, if your tire has a maximum PSI of 75, you can increase the pressure from 65 PSI to 70 PSI depending on the weight for towing. 

After you are done with towing, you should deflate the tires to the recommended PSI. 

Should I Fill My Trailer Tires To Max PSI

Yes, you should fill the trailer tires to the maximum pressure listed on the tire’s sidewall when it is cold. Trailer tires have a thicker sidewall which is less prone to flex when the tire is filled to the maximum PSI. The tire will also generate less heat. As a result, your trailer tire will wear less and you will get better gas mileage from your car.

Should Boat Trailer Tires Be Inflated To Max Psi?

Yes, to get the full weight capacity, the boat tires should be inflated to their max PSI. If you don’t fill a boat trailer tire to its full capacity, it can’t withstand the weight and the car will be more likely to face an accident. 

Should RV Tires Be Inflated To Max PSI?

In a normal situation, you should not inflate the RV tire to the max PSI. Keep it around the recommended level.

However, if you must load heavier weight than usual, you can inflate the RV tire to maximum PSI. This will help the tire to efficiently and safely carry the load. You have to make sure never to inflate the tire 10 PSI above the max pressure level.

Should I Fill My Tires To Max Psi In Winter?

No, even in winter, you should not fill the tires to the max PSI. However, it’s recommended to increase the PSI of your tire to 3 to 5 PSI higher than in the summer. As in the winter, the tire produces less heat resulting in lesser pressure than in summer. 

How Far Below Max PSI Should Your Tires Be?

The optimal PSI should be at least 25% below the max PSI level. In other words, you should only fill the passenger car tires to 75% of the maximum level unless you carry too much heavy weight or tow something. 

For example, if your tire’s sidewall says the maximum PSI is 48, you have to multiply it by 0.75. So you get, 48*0.75 = 36 PSI. So, you should inflate the tire to 36 PSI. 

However, when you are carrying a heavy load, you can be 90% to 95% closer to the maximum PSI level. For example, for maximum PSI of 48, you can inflate the tire to 48*0.90 = 43.2 PSI. 

FAQs

Conclusion 

Hopefully, you got the answer to your question, should I fill my tires to max PSI or not. Don’t forget to inspect your car on a monthly basis and make sure the tire is properly inflated. 

It’s time for me to bid farewell now. Have a great day!