Keeping your car tires correctly inflated is an important part of maintaining your car, but it can be confusing.
You might find that the PSI numbers printed on the tires don’t match the PSI numbers on the inside of your driver’s side door, or in the owner’s manual. The PSI number on the front tires doesn’t match the back tires.
Should all car tires have the same pressure? What is the right tire pressure for my car?
Let’s find out!
Should All Tires Have The Same Pressure?
Cars with front-wheel drive should have higher tire pressure on the front wheels. This is also to compensate for the weight of the engine in the front. For rear-wheel driven cars, they will sometimes have less psi on the rear wheels.
How to Find the Perfect PSI Tire Pressure for All of Your Car Tires:
The ideal PSI for both front and back tires is included in your car’s owner’s manual. You can also check it on each tire as they will indicate a max psi. However, note that you shouldn’t inflate your tires to the max psi level.
There is also a number written on each tire as a guideline, but this is for the tire in general rather than specific to the vehicle you own.
If you look in your owner’s manual you will find an exact optimal PSI for both front and back tires.
Usually, the front tires require a slightly higher tire pressure to compensate for the heavy engine located at the front of most vehicles (especially front-wheel-drive cars). That means the front tires will have a different optimal PSI than the back tires.
It is not true that all 4 of your car’s tires should have the same tire pressure. However, all the tires you buy for the same vehicle will require the same tire pressure, regardless of the tire manufacturer – the PSI specified in the car’s owner’s manual.
Why do Tires Have Different Pressures?
Weight is the major reason that cars have front and back tires with different ideal PSI.
More weight pushing down on the tire means more friction.
Friction generates heat, and heat means higher pressure. The tires that are expected to bear the majority of the vehicle’s weight are designed with this in mind.
Should Front or Rear Wheels Have The Highest PSI?
We see a huge shift toward rear-wheel-drive cars among electric cars.
So, seems like the industry is shifting away from the cheaper front-wheel-drive solution (as the engine typically is placed in the front – the cheaper option is to produce front-wheel-drive cars.)
This will be different for different vehicles.
Typically, if the engine is located at the front of the vehicle, the front tires will have a higher PSI to support the extra weight.
If a vehicle has an engine in the back, the back tires might require some extra tire pressure. Their ideal PSI might be higher than the front tires.
It’s impossible to answer this question without checking the vehicle’s owner’s manual. This will give you the exact PSI you need for both the front and back tires.
What Happens If You Drive With Too High or Low PSI?
Tire pressure can make a huge difference to your car’s handling and performance. Driving with underinflated tires puts you and the drivers around you in danger. When your car responds sluggishly in an emergency, people can get hurt.
According to Transport Canada statistics, a vehicle with tire pressure that is underinflated by 25% is up to 3 times more likely to be in an accident.
This makes sense according to tire experts at Kal Tire who set up real-world tests, according to Wheels.ca. They were able to pass the courses they set up with their tires properly inflated but failed the handling and turning tests when the tires were less than the required PSI.
Driving with your tires overinflated (with a PSI that is too high) isn’t as big an issue and won’t affect your car’s performance. If you are slightly above the optimal PSI, there is no reason to worry.
However, you can’t just fill up your tires as much as possible.
Each tire has a “maximum PSI” printed on the tire. This is much higher than the recommended PSI that is also printed. If you inflate the tire above this PSI, there is a possibility that the tire could blow out.
Do you Inflate Tires Equally On a Car with All-Wheel Drive?
If you have a car with all-wheel drive, all four of your car’s wheels are helping to move you on the road or wherever you are going.
That doesn’t mean that your tires are doing equal work.
Even if the engine is supplying as much power to the rear wheels as is to the front wheels, the vehicle is probably heavier on whichever end the engine is located. That means these tires are being pushed harder into the ground and are more prone to wear and tear over time.
You should consult your car’s owner’s manual for the precise PSI to use for each tire. Even if all 4 wheels are working together in an all-wheel drive, the tires are still balanced differently.
Should Tire Pressure Be Exact and Precise?
The more precise you can be with your car’s tire pressure, the closer you can get to ideal performance. Inflating your tires properly can make a big difference in your driving experience.
However, it’s not very easy to be exact about tire pressure, and the truth is that it doesn’t matter that much to most people.
The process of filling your tires (at least with a manual gauge) is inherently imprecise. Unless you’re very skilled (and even then) you release a little bit of air as you measure it, and when you put the cap back on.
If this were an important chemistry experiment that wouldn’t be okay, but we’re okay with a little bit of imprecision here.
Drastically underinflated or overinflated car tires are a major issue and can even be dangerous.
Underinflated tires can lead to significant performance problems and increased crashes. Overinflated tires can blow out.
Slightly underinflated or overinflated tires are not going to cause a problem for them.
Technically, being slightly off with your PSI can decrease your car’s performance – but the decrease is so slight that is most likely unnoticeable, even in tests.
It’s worth mentioning that overinflating your car tires is much better than underinflating them. Underinflated tires can cause a lot of problems, but being slightly higher than the recommended PSI is perfectly fine.
When Should Your FRONT Tires Have More Pressure?
If your car has an engine in the front, your front tires will probably have a higher ideal PSI.
This helps them support the weight of the vehicle better while maintaining a grip on the road.
This is also because the engine puts more weight on the front wheels.
Check your car’s owner manual for a precise ideal PSI for the front tires.
When Should Your REAR Tires Have More Pressure?
Vehicles with engines in the back sometimes have back tires with a higher ideal PSI. You can check in your vehicle’s owner’s manual for the ideal PSI for both front and back tires.
How and When Should I Test My Tire Pressure?
Tire pressure is very affected by heat, which means that getting a stable and reliable reading means you need to measure the pressure after the car has been sitting a while.
It is good to test the tire pressure when it is cold, and the car hasn’t been driven in a while.
Early in the morning is perfect.
You can check your tire pressure at auto parts shops, mechanics, or gas stations. If you want to check it at home you just need a gauge, an air compressor, and a pen.
Go around to all 4 tires and press the gauge into the valve to get a reading. Write it down, before removing the gauge and replacing the cap as quickly as possible.
You can compare these numbers with the ideal numbers in your car’s owner’s manual, and use an air compressor to fill the tires before testing again.
Keeping your tires properly inflated is important for your vehicle’s health and your safety.
You don’t need to be 100% exact, but you should be aiming for the optimal PSI numbers in your car’s owner’s manual, rather than the general recommended PSI written on the side of the tire.
Don’t expect all of the tires to be the same. The front and back tires are usually different and have different PSI requirements – even on an all-wheel-drive model.
When you reinflate your tires, it is better to overinflate slightly than to underinflate. Instead of focusing on getting the PSI to be perfectly exact, use that energy to check back regularly. You should check the pressure on your tires every month, or any time there is a change of more than 5 C in the climate around you.