**The Impact of Tire Pressure on Performance**

Tire pressure has a significant impact on a vehicle's performance, particularly when it comes to grip and handling on various road surfaces. In this article, we'll explore how tire pressure affects grip, hydroplaning, fuel economy, and tire wear.

**Grip and Handling**

When it comes to grip and handling, tire pressure plays a crucial role. On a dry track day, decreasing tire pressure can be beneficial as it allows for a larger contact patch, resulting in more grip. However, this is not the case when driving on wet roads. In the wet, hydroplaning occurs when the average pressure of the tire on the ground is equal to the average pressure of the water pushing back up on the tire. This creates a situation where the tire is essentially floating, resulting in loss of traction and control.

On dry roads, a properly inflated tire can maintain a larger contact patch, allowing for more grip and better handling. However, if the tire pressure is too low, the contact patch decreases, reducing the amount of pressure on the ground. This means that the tire will push onto the outside edge of the tire, resulting in decreased grip.

**Hydroplaning**

When driving on wet roads, hydroplaning can occur when the water piles up in front of the tire and the tire struggles to move it out of the way. If the tire pressure is too high, it increases the amount of pressure on the ground, making it more difficult for the tire to displace the water. This results in a higher likelihood of hydroplaning.

On the other hand, if the tire pressure is too low, the contact patch decreases, and the tire pushes onto the outside edge of the tire. This can cause the water to accumulate underneath the tire, resulting in increased pressure on the ground and a greater risk of hydroplaning.

**Fuel Economy**

When it comes to fuel economy, rolling resistance plays a significant role. Rolling resistance is the energy lost as heat when a tire deforms under load. The amount of rolling resistance is directly related to the tire pressure, with decreasing pressure resulting in increasing rolling resistance. According to Michelin's study, reducing the tire pressure by one bar (14.5 PSI) resulted in a 30% increase in rolling resistance and a corresponding 3-5% increase in fuel consumption.

As the tire pressure decreases, the rolling resistance increases exponentially, leading to greater fuel consumption. This means that if the tire pressure is not properly inflated, it can result in decreased fuel economy and increased fuel costs.

**Tire Wear**

Finally, tire wear is also affected by tire pressure. When a tire is properly inflated, the even distribution of air results in even wear on the tread surface. However, when the tire pressure is too low or too high, uneven wear patterns can occur.

On the other hand, if the tire pressure is too low, the center strip of the tire wears down more quickly due to increased pressure on that area. Conversely, if the tire pressure is too high, the edges of the tire wear down faster due to decreased contact patch and increased pressure on those areas.

In conclusion, tire pressure has a significant impact on a vehicle's performance, particularly when it comes to grip, hydroplaning, fuel economy, and tire wear. By understanding the effects of tire pressure on these factors, drivers can take steps to optimize their tire pressure for optimal performance and safety.

"WEBVTTKind: captionsLanguage: enhello everyone and welcome in this video we're going to be answering four questions about tire pressure first how does tire pressure change with temperature second how does tire pressure affect tire grip third how does tire pressure affect fuel economy and fourth how does tire pressure affect tire wear now modern cars come equipped with tire pressure monitoring systems but the feature is much more rare on older cars fortunately there's a clever solution as I heard about this steelmate tire pressure monitoring system from Chris fix and it's something you can easily install on nearly any car the system works by placing a pressure transducer at each tire and then this information is wirelessly sent to a receiver unit which plugs into the power outlet and displays each Tire's pressure the system can even inform you if you have an air leak in a tire so our first question how does tire pressure change with temperature and you may have heard a rule of thumb uh where every 10° of Fahrenheit change of ambient temperature you'll have one PSI of change in your tire pressure so where does this come from well it all comes from the ideal gas law and it's very simple equation that we can work out to prove this fact so we have PV equal nrt p is the absolute pressure within the tire V is the volume so it's constant n is the amount of gas within the tire this is in moles and this is also constant R is a gas constant which of course is constant and T is temperature so if we eliminate the constants we have P being proportional to T so uh pressure and temperature are directly proportional so let's take an example let's say you have a car uh and in the summer it's driving around you know the cold temperature is going to be about 80° F and then you know months pass and now it's winter and you haven't changed your tire pressure well you're probably going to have some air leak anyways but we're just going to be looking at the pressure differential just from that temperature change so now we're saying it's winter and it's 30° outside Fahrenheit so in kelvin this is 300 Kelvin down to 272 you do have to use Kelvin in this equation as it's the absolute uh rather than a different scale so our tire pressure we're going to say it's at 35 PSI now we have to add ambient pressure to that which is 14.7 PSI so we're just going to say about 50 uh absolute uh PSI inside the tire so now we have a very simple equation 300 over 272 this over this is equivalent to 50 over what so what's our pressure drop going to be well that gives us 45.3 or about 45 PSI so as you can see with a 10° drop or with a 50° drop uh in Fahrenheit we have a 5° drop in PSI so uh for every 10° we have one PSI now if you want this information in Celsius it's just going to be one PSI for every 5.6 de CSI change so how does tire pressure affect grip well let's say you're on a track day and it's sunny and dry in this case it can be beneficial to decrease your tire pressure because you can get a larger contact patch and as a result more grip that said the complete opposite can happen happen in the wet so here we're going to be talking about hydroplaning so we've got our tire here and it's traveling and there's water on the ground which piles up in front of the tire and that tire has to move that water out of the way in order to maintain grip with the ground so hydroplaning occurs when the average pressure of the tire on the ground is equal to the average pressure of the water pushing back up on that tire that makes sense because if they're equal it means it's basically going to be floating so now keeping that in mind A tire's pressure will directly affect its average pressure it's putting down on the ground so if you increase the tire pressure you're going to increase the amount of pressure on the ground because you're going to decrease the contact patch and so you're going to have more pressure on that area so there's a direct link between your tire pressure and the likelihood of your car to hydroplaning so the higher your tire pressure the lower the likelihood of you are uh to hydroplane and the lower that tire pressure it's significantly increases the chances of you hydroplaning so what does this actually look like well if you're looking at the front of the car and you've got the correct tire pressure you can see that that water will move outside around it and you'll also have Treads which it can move through but if you have too low of a tire pressure you're going to start resting on the outside edge and you'll have this kind of concave area where the water starts to flow underneath the tire because the pressure is too low and so it'll build up underneath there and you can begin to hydroplane now you can also look at this from a perspective of the contact patch so if you're looking down on the contact patch here if you have a properly inflated either one of these options where it can flow around around here it may be more difficult for it to flow around but that's why you're going to have Treads and things like that so the water can pass underneath but if you know it's too deflated that tire is a really low tire pressure you can see that contact patch will start to push to the outside of the tire and you can have that water flow underneath so it's very important to maintain um a decent tire pressure you know what your manufacturer recommends for your car in order to prevent your vehicle from hydroplaning moving on to number three how does tire pressure affect fuel economy and in order to understand that we need to understand rolling resistance so rolling resistance is the energy lost as heat when a tire deforms so it's compressed and then it stretches back out and in that deformation it loses some of that energy as heat and so that's rolling resistance and that's going to be a force that your car has to overcome in order to drive so there's actually a very strong relationship between rolling resistance and the pressure in your tire and it's actually an exponential function so as you decrease uh the amount of rolling resistance you have exponentially increases so Michelin did a study and they reduced the tire pressure of a tire by one bar or 14.5 PSI uh from what the manufacturer had set it at and they noticed a 30% increase in the rolling resistance and this equates to about a 3 to 5% greater amount of fuel consumption and as I mentioned this only gets worse so as you keep continuing uh to decrease pressure you exponentially gain rolling resistance and that means you exponentially gain how much fuel consumption you're going to have and our our final question how does tire pressure affect tire wear so we've got three different scenarios here a properly inflated Tire an overinflated tire and an underinflated tire and so looking at each of these the properly inflated Tire you're going to have even wear and you're going to have a nice contact patch an overinflated Tire you're going to have more pressure on the center of the tire and as a result you're going to wear down that center strip and have wear on the center of the tire rather than an even distribution of the wear and then an underinflated Tire you're actually going to have increased pressure on the outsides of the tire on the edges and so as a result you're going to wear out those edges first on that tire so thank you all for watching be sure to check out the video description for a link to the product which I used in this video and if you have any questions or comments feel free to leave them belowhello everyone and welcome in this video we're going to be answering four questions about tire pressure first how does tire pressure change with temperature second how does tire pressure affect tire grip third how does tire pressure affect fuel economy and fourth how does tire pressure affect tire wear now modern cars come equipped with tire pressure monitoring systems but the feature is much more rare on older cars fortunately there's a clever solution as I heard about this steelmate tire pressure monitoring system from Chris fix and it's something you can easily install on nearly any car the system works by placing a pressure transducer at each tire and then this information is wirelessly sent to a receiver unit which plugs into the power outlet and displays each Tire's pressure the system can even inform you if you have an air leak in a tire so our first question how does tire pressure change with temperature and you may have heard a rule of thumb uh where every 10° of Fahrenheit change of ambient temperature you'll have one PSI of change in your tire pressure so where does this come from well it all comes from the ideal gas law and it's very simple equation that we can work out to prove this fact so we have PV equal nrt p is the absolute pressure within the tire V is the volume so it's constant n is the amount of gas within the tire this is in moles and this is also constant R is a gas constant which of course is constant and T is temperature so if we eliminate the constants we have P being proportional to T so uh pressure and temperature are directly proportional so let's take an example let's say you have a car uh and in the summer it's driving around you know the cold temperature is going to be about 80° F and then you know months pass and now it's winter and you haven't changed your tire pressure well you're probably going to have some air leak anyways but we're just going to be looking at the pressure differential just from that temperature change so now we're saying it's winter and it's 30° outside Fahrenheit so in kelvin this is 300 Kelvin down to 272 you do have to use Kelvin in this equation as it's the absolute uh rather than a different scale so our tire pressure we're going to say it's at 35 PSI now we have to add ambient pressure to that which is 14.7 PSI so we're just going to say about 50 uh absolute uh PSI inside the tire so now we have a very simple equation 300 over 272 this over this is equivalent to 50 over what so what's our pressure drop going to be well that gives us 45.3 or about 45 PSI so as you can see with a 10° drop or with a 50° drop uh in Fahrenheit we have a 5° drop in PSI so uh for every 10° we have one PSI now if you want this information in Celsius it's just going to be one PSI for every 5.6 de CSI change so how does tire pressure affect grip well let's say you're on a track day and it's sunny and dry in this case it can be beneficial to decrease your tire pressure because you can get a larger contact patch and as a result more grip that said the complete opposite can happen happen in the wet so here we're going to be talking about hydroplaning so we've got our tire here and it's traveling and there's water on the ground which piles up in front of the tire and that tire has to move that water out of the way in order to maintain grip with the ground so hydroplaning occurs when the average pressure of the tire on the ground is equal to the average pressure of the water pushing back up on that tire that makes sense because if they're equal it means it's basically going to be floating so now keeping that in mind A tire's pressure will directly affect its average pressure it's putting down on the ground so if you increase the tire pressure you're going to increase the amount of pressure on the ground because you're going to decrease the contact patch and so you're going to have more pressure on that area so there's a direct link between your tire pressure and the likelihood of your car to hydroplaning so the higher your tire pressure the lower the likelihood of you are uh to hydroplane and the lower that tire pressure it's significantly increases the chances of you hydroplaning so what does this actually look like well if you're looking at the front of the car and you've got the correct tire pressure you can see that that water will move outside around it and you'll also have Treads which it can move through but if you have too low of a tire pressure you're going to start resting on the outside edge and you'll have this kind of concave area where the water starts to flow underneath the tire because the pressure is too low and so it'll build up underneath there and you can begin to hydroplane now you can also look at this from a perspective of the contact patch so if you're looking down on the contact patch here if you have a properly inflated either one of these options where it can flow around around here it may be more difficult for it to flow around but that's why you're going to have Treads and things like that so the water can pass underneath but if you know it's too deflated that tire is a really low tire pressure you can see that contact patch will start to push to the outside of the tire and you can have that water flow underneath so it's very important to maintain um a decent tire pressure you know what your manufacturer recommends for your car in order to prevent your vehicle from hydroplaning moving on to number three how does tire pressure affect fuel economy and in order to understand that we need to understand rolling resistance so rolling resistance is the energy lost as heat when a tire deforms so it's compressed and then it stretches back out and in that deformation it loses some of that energy as heat and so that's rolling resistance and that's going to be a force that your car has to overcome in order to drive so there's actually a very strong relationship between rolling resistance and the pressure in your tire and it's actually an exponential function so as you decrease uh the amount of rolling resistance you have exponentially increases so Michelin did a study and they reduced the tire pressure of a tire by one bar or 14.5 PSI uh from what the manufacturer had set it at and they noticed a 30% increase in the rolling resistance and this equates to about a 3 to 5% greater amount of fuel consumption and as I mentioned this only gets worse so as you keep continuing uh to decrease pressure you exponentially gain rolling resistance and that means you exponentially gain how much fuel consumption you're going to have and our our final question how does tire pressure affect tire wear so we've got three different scenarios here a properly inflated Tire an overinflated tire and an underinflated tire and so looking at each of these the properly inflated Tire you're going to have even wear and you're going to have a nice contact patch an overinflated Tire you're going to have more pressure on the center of the tire and as a result you're going to wear down that center strip and have wear on the center of the tire rather than an even distribution of the wear and then an underinflated Tire you're actually going to have increased pressure on the outsides of the tire on the edges and so as a result you're going to wear out those edges first on that tire so thank you all for watching be sure to check out the video description for a link to the product which I used in this video and if you have any questions or comments feel free to leave them below\n"