What Tire Pressure is Too Low?
No less than 11,000 vehicle crashes are caused by tire-related issues in the US alone. Every year 200 people die in these crashes.
Did you know that a car is three times more likely to crash in a tire-related accident if its tires are under-inflated by more than 25%? According to a survey by National Highway Traffic Safety Administration (NHTSA), every 3rd vehicle has at least one underinflated tire.
The point to be taken is that low tire pressure is a very critical issue. But how do you know that tire pressure is too low? In this article, we’ll try and determine the minimum threshold for tire pressure, symptoms of low tire pressure, and safety hazards linked to it.
What Tire Pressure is Too Low?
A general rule of thumb is that your tire pressure will be termed as low if it is 10% below the recommended value by the manufacturer. Most SUVs, sedans, and light trucks recommend 33 psi to be adequate tire pressure. Hence if your tire pressure falls below 30 psi then it will be considered as under-inflated. Most of the hatchbacks come with a pressure rating of 30 psi for all four tires. So, you should avoid driving it if the pressure is less than 27 psi.
If you’re not sure about the recommended pressure rating for your car then you can take a look at the door post pillar or glove box compartment. Most of the manufacturers have pasted a sticker to indicate the normal pressure range for that vehicle. If you are unable to find these values in your car, then you should probably look in the owner’s manual. You can find it there under the day-to-day maintenance section.
Tire pressure is a subjective matter and it can be impacted by many factors, including:
- Temperature
- Vehicle
- Tire size
- Load in the vehicle
- Average driving speed
We have discussed the impact of vehicle type on tire pressure above in detail. Let’s take a closer look at temperature as it greatly affects the values of pressure in the tire. What makes temperature so important is the fact that it varies through the day and you have no control over it. For every drop of 10 degrees in outside temperature, the pressure is reduced by 1 psi in the tire. The recommended tire pressure is 35 psi at 75 degrees. If the temperature falls below 25 degrees then the effective pressure left in the tire will be 30 psi. The same scenario is applicable when the temperature rises above 100 degrees during summer. So, the best way to cope with this variance is to maintain tire pressure according to the average temperature. This way you can avoid under or over-inflation to a great extent.
What Are the Symptoms of Low Tire Pressure?
Low tire pressure doesn’t reveal itself openly. You would feel the symptoms only when it has fallen considerably. Hence, you must keep an eye on the slightest indications of low tire pressure and act accordingly to contain further damage.
Tire Pressure Monitoring System (TPMS): The purpose of the tire pressure monitoring system is to give a warning when pressure falls below the described limit. These systems are set to post a warning if the tire pressure falls by 5%. So, you have some leeway after receiving a warning. But in the meantime, you should look for other symptoms to determine the severity of the situation.
Reduced Braking Traction: When the tires of your car are under-inflated, you’ll feel that your car isn’t stopping when it’s supposed to be. The prime reason is that reduced pressure in tires greatly decreases the braking traction. So, car braking will take more distance than usual before stopping.
Delayed Steering Response: A delayed steering response is another indication of under-inflated tires. On twisted terrains, your steering would become a lot heavier and resistant towards turning. This can happen especially when you’re driving a car with power steering. Delayed steering response can also be caused by issues of the steering system, so always watch out for other symptoms in combination.
Shaky Suspension: Under-inflated tires can cause a bumpy ride even on flat tracks. You might feel unnecessary jerks and your riding comfort is highly compromised.
Downsides of Driving With Low Tire Pressure
Driving a car with low tire pressure isn’t only dangerous but it has economical side effects too, in the longer run. Some of the downsides of riding with low tire pressure are:
Reduced Fuel Economy: Under-inflated tires hinder the smooth operation of the car. As they increase the area of contact between tire and road. The coefficient of friction is increased as a result. Due to which more power is drawn from the engine to counter that frictional force. Hence, more fuel is consumed and mileage is decreased.
Increased Risk of Puncture: More area contacting the ground means more chances of picking a nail or sharp object that might puncture the tire.
Faster Tire Wear: Tires tend to run heavier when they are under-inflated. The rubbing action of tire and road is increased. As a result, you might end up wearing out your tires way sooner than expected.
Compromised Handling: Your handling would not be the way it used to be. Under-inflation of tires can lead to severe discomfort while driving. You will feel exhausted due to delayed response and stiff handling of the car.
Is it Safe To Drive with Low Tire Pressure?
It is extremely dangerous to drive with low tire pressure. Once you’ve established the fact that your tire pressure is too low to drive then you must take care of that immediately.
Under-inflated tires pose the greatest threat of blowouts. As the area of contact between rubber and road is increased, this constant rubbing increases the local temperature of the tire. You need to look out for this hazard during extreme summers and highway driving. During these scenarios, tire temperature is already touching the upper limits. So, the temperature added due to under-inflated tire causes a sudden blowout. This is the lead cause of crashes in car-related accidents. So, you must always avoid driving with under-inflated tires.
