The tires on your car are arguably the most important component, as without them you can’t get anywhere no matter how big your engine is. Taking care of your tires is essential, and it is important to know what the effects are of underinflating or overinflating your tires.
The 4 symptoms of over-inflated tires are:
- Lack of traction
- Excessive wear on center treads
- An uncomfortable ride
- The car behaving oddly
Below, we will look at why your tires might be over-inflated, and some good practices to ensure you always have the right amount of pressure in yours. We will then discuss the effect of having too much air in your tires, as well as too little.
What Is Tire Pressure?
Many people drive their car every single day and have no idea what pressure their tires are at, or why it is important. The air in your tires is what allows you to drive at speeds of more than a few miles per hour, as deflated tires provide not just an unstable and dangerous ride, but also a slow one, as they offer too much resistance against the road surface.
But it is not just speed you should be thinking about when considering how much air is in your tires, as it is just plain dangerous to be driving around with the incorrect tire pressure. Tire pressure is measured in pounds per square inch (PSI) or bar. Your car will have its own specified pressure to which you should inflate your tires, with the fronts usually requiring more pressure than the rears.
The Effect Of Weight
This is because the engine is usually in the front, and thus more of the car’s weight is over the front tires. The tires’ ability to carry the weight of the car is proportional to the pressure inside of it, so for more weight the tires need to be of a higher pressure. In cars with most of the weight in the rear, the rear tires will need to be at a higher pressure than the front tires.
The reason for this is all about the contact patch that the tire has with the road. The contact patch is the section of the tire that is touching the road at any one time. It is the only point of contact (well, one of four, with one on each tire) that your car has with the road. Thus, maintaining the correct tire pressure will ensure you have the optimum amount of grip.
However, tire pressure doesn’t just correspond to grip levels, as there are other safety implications of incorrect pressure. Let’s take a look at each case in more detail.
Over-inflated tires can have a massive impact on your ability to control the car, and thus your safety as well. Not only will your car drive differently, but you will also be putting yourself at higher risk of having a tire blow out. Think of it like blowing up a balloon: as you put more air into it the balloon, will become much easier to pop.
A tire blowout could prove fatal if you are driving at high speed, but there are other symptoms of over-inflated tires that can also pose real risks. Let’s take a look at them in more detail below.
4 Symptoms Of Over-Inflated Tires
1. Lack Of Traction
The first sign that your tires are over-inflated is a loss of traction. As we stated in the previous section, the contact patch of your tires is what gives your car the grip. When your tires are over-inflated, this contact patch becomes smaller as the center of the tire begins to bulge. This means it is only the center couple of inches that will be in contact with the road.
Smaller Contact Patch
This will cause you to lose grip, as the smaller the contact patch, the less grip that is offered. As you go around corners you may begin to feel the car want to slide slightly, or you may find that your braking distances increase. But you shouldn’t wait to see what the handling is like while driving. Instead, you should regularly check out your tire treads.
2. Excessive Wear On Center Treads
By checking your tire treads regularly, you will begin to notice if the center treads are worn out significantly more than those on the outside and inside of the tire. If you have been driving with over-inflated tires for a while, the center treads will have been doing most of the work in terms of the contact patch, and so will most likely be far more worn than the surrounding treads.
Legal Tread Limits
There are legal limits as to how much tread you must have on your tires, and this is measured by depth, across the full tire. So, even if you have more than enough tread on the outside and inside of the tire, if your center treads are worn down beyond the limit you could be breaking the law. Not only are your treads important for grip, and thus safety, you also don’t want to be driving illegally.
3. An Uncomfortable Ride
Along with a potential decrease in grip, you will also probably notice a more uncomfortable ride with over-inflated tires. This is because over-inflated tires are stiffer and less flexible than those filled to the correct levels. Stiffer tires will transfer more of the bumps from the road to you and your passengers, while a properly inflated tire will absorb more of the shock.
It won’t be quite as noticeable as if you were to be driving with a broken suspension system for example, but if you spend a lot of time driving on uneven surfaces you will definitely feel it more. If you are racing, the high speeds will ensure you feel even the smallest of bumps in the road, and so it won’t just be dangerous, it will also be very uncomfortable.
4. The Car Behaving Oddly
Finally, aside from a loss of traction and the car feeling very uncomfortable to drive, you may also find that it behaves a bit differently to what you are used to. This is because systems like the ABS and traction control are tuned to work with tires that are filled with the correct amount of air.
Not Designed For It
If you overfill your tires, your electronic stability control systems may begin to act in strange ways, as they may pick up incorrect signals from the wheels, and thus try to control the car in seemingly weird ways. This could prove to be very dangerous, and it is yet another reason you should ensure you always fill your tires with the right amount of air.
Under-inflated tires can prove to be just as dangerous as over-inflated tires for similar reasons. For instance, a heavily under-inflated tire can also have a smaller contact patch, as the tire can deform more under the weight of the car and thus the full width of the tire might not be in contact with the road. This will also cause the tire tread to wear out in an uneven fashion.
This can cause a lack of grip, and it can also make your car far less fuel efficient. Under-inflated tires can offer more resistance to the road, and thus make it harder for your car to push itself forwards. This results in higher fuel consumption, but it can also make your car’s handling unpredictable, with braking distances affected and an inhibited ability to turn the car.
Always Inflate Your Tires Properly
It is clear that both over-inflating and under-inflating your cars’ tires is a bad idea. Only in extreme cases will you be able to tell if a tire is under or over-inflated just by looking at it, as anything less than 10 PSI either way is pretty much undetectable to the eye. The only way to do it properly is by using a tire pressure gauge.
At Least Once A Month
You should aim to check your tire pressures at least once a month, and definitely before any long drives. This will go a long way towards preventing any possible danger while driving and minimize your risk of a blowout. But there are a few other things to bear in mind when you are checking your tire pressures.
Effect Of Temperature
Higher temperatures will cause your tires to naturally increase in pressure, due to the proportional relationship between pressure and temperature. Thus, you should always check your tires before driving, as they will heat up with the friction from the road, giving you a higher reading than when they are cold. You should also check them in the morning, before it gets warmer during the day.
Manufacturers will provide their recommended tire pressures for your car assuming you are checking them cold, and so always try to do so in a cool environment. If you live somewhere very hot, check the manufacturer’s guidelines and try to find out what their recommendations are for different climates, as a 10°C difference can mean a difference in pressure of around 1 PSI.
Check The Manufacturer’s Guidelines
You will also see that your manufacturer’s guidelines are for various different tire types, so you want to make sure you are filling your tires up correctly for your specific tires. There will also be different guidelines depending on how many people you will usually have in your car, and where they will be seated. This is once again to do with the weight on each tire.
If you are travelling a long distance and need to bring lots of heavy bags with you in the trunk, check what the manual suggests for the rear tires, as it will probably be an increase versus the pressure for normal driving with no passengers or extra weight. Just remember to let some air out afterwards, so you don’t end up driving with over-inflated tires without the extra weight!
Tire pressures are very important to maintain, and there are a few signs you can look out for if you think your tires might be over-inflated. Short of simply checking your tire pressures against the manufacturer’s guidelines, you will notice uneven tread wear, decreased traction and possibly an uncomfortable ride too.
You may also notice your car’s ESC systems acting slightly odd, but all these symptoms are also experienced with under-inflated tires as well. Thus, it is vital that you check your tire pressures regularly and monitor your tread too. Driving without the correct pressure in your tires can cost you more money in terms of fuel, but it will also make driving far more dangerous for you as well.