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Summary
  • It’s not recommended to drive on 20 psi tire pressure, unless in an emergency, as it could accelerate air loss in the tire.
  • The recommended tire pressure is somewhere between 32 and 36 psi, but it could vary per vehicle.
  • Tire blowout and reduced fuel economy are two issues that could occur if you drive with low tire pressure.

Tire pressure affects your car’s fuel economy, its handling, and the lifespan of its wheels. It’s important to keep the pressure at the manufacturer-recommended level by inflating the tires whenever they look deflated or when the low tire pressure light activates.

However, there are situations when you need to drive on tires with low pressure. In those emergencies, what tire pressure is too low to drive on?

What Tire Pressure Is Too Low For Safe Driving?

20 pounds per square inch (psi) is the minimum tire pressure that you can conceivably continue to drive your car on. If the pressure drops below even that, the tire should be considered flat.

half and fully inflated tires comparison
Note: A tire can look practically normal with only half the pressure it’s supposed to have. | Image Source: Richard McCuistia

Driving on 20 psi tire pressure is not something you should do and is not recommended except in an emergency. Tires constantly lose air, which causes pressure to drop, and driving hastens the process of air loss.

As soon as possible, inflate the affected tires back to the safer pressure level shown on the vehicle’s tire information decal.

What Is The Recommended Tire Pressure?

In general, it’s advised to maintain tire pressure between 32 and 36 psi, but this value may vary depending on the vehicle. This pressure range keeps the tires firm enough to support your car’s weight while avoiding straining the materials that make up the tire.

How Does Temperature Affect Tire Pressure?

Have you ever gone to bed knowing that your car’s tire pressure was fine and woken up to find it had either drastically dropped or risen? That’s because the temperature outside the tires can change the tire pressure. Every 10 degrees Fahrenheit of temperature change will alter the pressure by one psi.

Rising temperatures will make air expand in volume. Heated air exerts more force against the tire’s interior, which translates to increased tire pressure.

Conversely, temperature drops will cause air to contract. This reduces tire pressure.

Whenever you measure tire pressure, check the temperature outside your car. If it gets hotter or colder, the pressure levels inside the tires will change accordingly. In hot weather, tires with low pressure might seem fine.

Why Should You Avoid Driving With Low Tire Pressure?

It’s not recommended to drive your car if the tire pressure is too low. Otherwise, the following issues can take place:

Tire Blowout

Underinflated tires can blow out while driving at higher speeds. The sidewalls of tires with low air pressure flex more often, making their interior hotter. If the interior gets too hot, part of the tire’s rubber can violently separate from it. The ensuing blowout can cause you to lose control of your car.

, What Tire Pressure Is Too Low For Safe Driving? Possible Issues, Recommended Tire Pressure

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Driving with low tire pressure strains the sidewalls of the tire. On lower profile tires, if you drive a long way with a tire underinflated, simply reinflating the tire can cause it to blow out.

Reduced Fuel Economy

Driving with low tire pressure increases the fuel consumed by your car. Low air pressure makes the tires softer and less capable of rolling. The engine needs to work harder to rotate soft tires, so it burns more fuel to produce more power.

Degraded Handling

When an underinflated tire’s sidewall flexes, its tread also writhes. Since the tread serves as the point of contact between the tire and the road surface, its writhing reduces the tire’s stability and traction. Tires with low air pressure respond more slowly and clumsily to inputs from the steering wheel and your car needs more room to brake itself.

Shorter Tire Service Life

Tires with insufficient air pressure have shorter service lives. Low tire pressure warps the tire’s footprint, making its inner and outer shoulders wear out faster. You will have to replace the prematurely worn-out tire before it causes even more problems.

While it’s possible to drive with low tire pressure, you should only do so in an emergency. Try to inflate the tires as soon as possible.

About The Authors
Written By Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

File Under : DIY , Wheels and Tires
Garage Essentials
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