Why Do Cars That Sit Get Flat Tires? Effects Of Duration And Tire Maintenance [Update On 2025]

Cars that sit can get flat tires because their weight compresses the tires against the ground, creating flat spots. Temperature changes also affect air pressure inside the tires. Maintaining the recommended air pressure and regularly checking tire care can prevent flat spots and improve tire life.

The duration of inactivity plays a significant role in tire degradation. Tires that sit for weeks or months may experience uneven wear. This unevenness can cause the tires to develop flat spots. Flat spots occur when the weight of the car rests on the same part of the tire for too long.

Proper tire maintenance can mitigate these issues. Regularly checking tire pressure and inflating tires to the recommended levels is essential. Rotating the tires and storing the car on jack stands can also help maintain their shape.

In summary, duration of inactivity and inadequate tire maintenance can lead to flat tires. The next section will explore effective methods for protecting tires during long periods of storage, ensuring optimal performance when the car is back on the road.

Table of Contents

What Are the Main Causes of Flat Tires in Cars That Sit?

Flat tires in cars that sit primarily occur due to a combination of factors such as temperature changes, under-inflation, and degradation of materials over time.

The main causes of flat tires in parked cars are as follows:
1. Under-inflation
2. Temperature fluctuations
3. Tire age
4. Environmental factors
5. Lack of movement

To understand these causes more deeply, each aspect will now be discussed.

Under-inflation: Under-inflation leads to flat tires as the air pressure in the tires decreases over time. According to the National Highway Traffic Safety Administration (NHTSA), tires can lose around 1 PSI (pound per square inch) of air each month when idle. Insufficient air pressure increases the surface area in contact with the ground, which can result in flat spots or complete tire failure.
Temperature fluctuations: Temperature changes can impact tire pressure and flexibility. As the temperature drops, the air in the tire contracts, reducing pressure. The American Automobile Association (AAA) suggests that for every 10°F drop in temperature, tire pressure can drop by 1 PSI. Consequently, cars left in cold weather without monitoring tire pressure may experience flat tires.
Tire age: Tire materials degrade over time, even without use. The Rubber Manufacturers Association states that tires generally should not be used beyond six years from the date of manufacture. Aged tires can develop cracks or bulges, making them susceptible to flats, regardless of mileage.
Environmental factors: Environmental conditions such as exposure to UV rays, moisture, or chemicals can contribute to tire deterioration. For instance, tires parked on grass may rot faster due to moisture. Similarly, prolonged sunlight exposure can damage the rubber compound, leading to premature aging and failure.
Lack of movement: Tires that sit for long periods can develop flat spots. Continuous weight on a stationary tire can lead to deformation. Even a slight compression can cause the tire to lose its round shape, affecting performance. The Tire Industry Association recommends moving parked vehicles periodically to maintain tire health.

Addressing these factors provides owners with actionable steps to prevent flat tires in cars that remain stationary for extended periods. Regular maintenance and monitoring can significantly reduce the risk of tire-related issues.

How Does Tire Age Contribute to Flat Tires in Inactive Cars?

Tire age significantly contributes to flat tires in inactive cars. Tires degrade over time due to various factors, including exposure to sunlight, ozone, and environmental conditions. This degradation can lead to changes in the rubber compounds, making them brittle. Brittle tires are more likely to develop cracks and leaks, which can result in air loss.

Inactive cars do not experience the regular flexing and movement that keeps tires conditioned. Prolonged inactivity accelerates the aging process, causing deterioration without the benefit of regular use. Additionally, air pressure tends to drop when a car is not driven. Lower tire pressure increases the risk of pinching or bottoming out, which can cause punctures or flat tires.

Furthermore, storing a vehicle in damp or uneven conditions can lead to flat spots on the tires. These flat spots can become permanent if the car remains stationary for an extended period. Thus, both age and inactivity contribute significantly to the likelihood of flat tires in cars that are not regularly driven. Regular inspections and maintenance are essential to mitigate these issues.

What Role Does Dry Rot Play in Tire Decline While Parked?

Dry rot plays a significant role in tire decline while parked by causing damage to the rubber over time. This degradation can lead to potential tire failure and safety hazards.

The main points related to dry rot in tires include:
1. Definition of dry rot
2. Environmental factors contributing to dry rot
3. Effects of dry rot on tire structure
4. Prevention measures for dry rot

Understanding these components is essential for grasping the full impact of dry rot on parked tires, including preventative strategies to maintain tire health.

Definition of Dry Rot:
Dry rot refers to the deterioration of rubber due to environmental exposure and age. This condition arises when tires are subjected to conditions like UV light, oxygen, and temperature fluctuations. The Rubber Manufacturers Association states that tires can begin to show signs of aging and dry rot as early as six years from the date of manufacture.
Environmental Factors Contributing to Dry Rot:
Environmental factors play a crucial role in the onset of dry rot. UV rays from the sun, high temperatures, and ozone exposure can accelerate the breakdown of tire rubber. According to a study by the Tire Industry Association in 2019, prolonged exposure to such elements can lead to aging, crack formation, and ultimately dry rot.
Effects of Dry Rot on Tire Structure:
Dry rot negatively impacts tire structure by causing cracks or splits in the tread and sidewalls. This damage compromises the integrity and performance of the tire. A 2021 study published in the Journal of Rubber Science found that tires with advanced dry rot face a significant increase in blowout risk when subjected to normal driving conditions.
Prevention Measures for Dry Rot:
Preventing dry rot involves specific maintenance practices. Proper tire storage in cool, dry, and shaded areas can reduce the risk of dry rot. Regularly inspecting tires for signs of aging and keeping them inflated at the appropriate pressure also helps extend tire life. The National Highway Traffic Safety Administration recommends checking tires at least once a month and replacing them every six years, regardless of use.

Are Faulty Valve Stems a Common Issue for Inactive Vehicles?

Yes, faulty valve stems are a common issue for inactive vehicles. Over time, vehicles that sit idle can experience degradation in various components, including valve stems, which can lead to air leaks in tires.

When comparing active and inactive vehicles, inactive vehicles often face more problems due to prolonged lack of use. Active vehicles receive regular movement, which helps maintain the flexibility of rubber parts like valve stems. In contrast, inactive vehicles experience rubber deterioration from environmental exposure and lack of lubrication. As a result, valve stems in inactive vehicles may become brittle or develop cracks, leading to air leaks. Additionally, regular tire checks in active vehicles can catch minor issues, whereas inactive vehicles may not be inspected regularly.

On the positive side, addressing faulty valve stems is relatively straightforward. Recognizing and replacing faulty valve stems can enhance tire performance and prolong tire lifespan. Regular vehicle maintenance, including tire inspections, contributes to safer driving conditions. Statistics from the Rubber Manufacturers Association indicate that proper tire maintenance can improve fuel efficiency by approximately 3% and enhance road safety.

On the negative side, replacing valve stems requires investment and attention. If neglected, faulty valve stems can lead to tire deflation and potentially dangerous driving situations. A study conducted by the National Highway Traffic Safety Administration (NHTSA) in 2020 found that improper tire maintenance, including issues with valve stems, contributes to 12% of all vehicle crashes annually. This highlights the importance of regular checks, especially for vehicles that are not driven frequently.

To prevent problems with valve stems in inactive vehicles, regular maintenance is crucial. Owners should periodically inspect tires and valve stems, even if the vehicle is not in use. It is recommended to check for cracks or leaks and to maintain proper tire pressure. Additionally, using valve stem caps can protect stems from dirt and debris. For long-term inactive vehicles, consider removing the tires and storing them properly to avoid damage to the valve stems.

How Does the Duration of Inactivity Affect Tire Health?

The duration of inactivity affects tire health in several significant ways. Prolonged periods without movement can lead to flat spots on tires. These flat spots develop when the weight of the vehicle compresses the tire in one area. The longer the tires remain stationary, the more pronounced these flat spots can become. Additionally, tires can experience a loss of air pressure over time. This reduction in pressure can lead to increased stress on the tire structure.

Moreover, prolonged inactivity can also allow for the degradation of the rubber. Tires contain compounds that can break down when exposed to environmental factors like sunlight and ozone. This breakdown reduces the tire’s elasticity and can lead to cracking. Thus, it is crucial to maintain tire health by regularly moving the vehicle or, at a minimum, periodically inspecting the tires for pressure and wear. Overall, the impact of inactivity is detrimental, and proactive measures can help prolong tire life.

What Are the Effects of Short-Term Parking on Tire Condition?

The effects of short-term parking on tire condition include potential flat spots, pressure loss, and uneven wear patterns.

Flat spots
Pressure loss
Uneven wear patterns

Short-term parking can lead to various impacts on tire condition.

Flat Spots: Flat spots occur when a tire remains stationary under load for an extended period. This can happen when a vehicle is parked for weeks or months. The weight of the car can cause a temporary flattening of the tire at the contact point with the ground. According to the Tire Industry Association, flat spotting generally represents a minimal issue for cars parked for just a few days. However, parking for several weeks can result in more noticeable unevenness, potentially affecting driving performance.
Pressure Loss: Pressure loss can happen naturally over time. Tires can lose about 1 pound per square inch (psi) of pressure per month. If a car is parked short term and does not receive regular checks, even a small psi loss can hinder tire performance. The U.S. Department of Transportation advises that under-inflated tires may decrease fuel economy and produce more heat, leading to a higher risk of blowouts. For these reasons, keeping tires inflated properly during parking periods, even short ones, is essential.
Uneven Wear Patterns: Uneven wear patterns can develop if the vehicle is parked in an abnormal position for an extended period. For example, if one tire is consistently underinflated or if the vehicle is slightly out of alignment, wear can develop unevenly across the tire surface. Research from the National Highway Traffic Safety Administration indicates that unevenly worn tires can lead to diminished handling performance and increased risk of tire failure, especially if combined with aggressive driving or harsh weather conditions.

In summary, while the effects of short-term parking are generally minimal, they require attention to ensure optimal tire performance and longevity. Regular maintenance, including tire rotations and pressure checks, is crucial in mitigating the risks associated with short-term parking.

How Does Long-Term Inactivity Deteriorate Tire Integrity?

Long-term inactivity deteriorates tire integrity through several key factors. First, tires lose air pressure when not in use. Air leaks occur through tiny pores in the rubber. Lower air pressure increases the risk of flat spots forming. Flat spots happen when the weight of the vehicle compresses the tire in one position for an extended period.

Next, oxidation affects the rubber compound. Tires are susceptible to exposure to oxygen and ozone in the air. Over time, these elements cause degradation of the rubber, leading to cracks and weakened structure. This deterioration can compromise the tire’s overall safety and performance.

Additionally, prolonged inactivity can lead to moisture accumulation. If a car sits in a damp environment, tire moisture can promote corrosion of the wheels. Corroded wheels can lead to air loss and tire damage.

Finally, sunlight exposure can harm tires as well. Ultraviolet rays can cause the rubber to dry out and become brittle. This brittleness reduces the tire’s flexibility and integrity.

In summary, long-term inactivity leads to loss of air pressure, oxidation of the rubber, moisture accumulation, and damage from sunlight. These factors collectively diminish tire integrity and can result in flat tires or even tire failure when the vehicle is finally in use.

What Factors Related to Tire Pressure Influence Flat Tires?

Flat tires can be influenced by several factors related to tire pressure. Maintaining the correct tire pressure is essential for preventing flats.

Under-inflation of Tires
Over-inflation of Tires
Temperature Fluctuations
Tire Age and Wear
Road Conditions

The relationship between tire pressure and flat tires encompasses various aspects. Understanding how each factor affects tire integrity is crucial for safe driving.

Under-inflation of Tires:
Under-inflation of tires occurs when the tire pressure is below the recommended level. When tires are under-inflated, they cannot support the vehicle’s weight properly. This situation increases tire wear and leads to overheating. According to the National Highway Traffic Safety Administration (NHTSA), under-inflated tires account for about 20% of tire-related accidents. For example, a study by the Rubber Manufacturers Association reveals that maintaining proper tire pressure can improve fuel efficiency by up to 3.3%.
Over-inflation of Tires:
Over-inflation of tires happens when the tire pressure exceeds the manufacturer’s recommended level. This condition makes tires rigid and less able to absorb road impacts. Over-inflated tires can lead to a higher risk of blowouts or flats, especially on uneven surfaces. A report by Consumer Reports indicates that over-inflated tires may wear unevenly, reducing tire lifespan and safety.
Temperature Fluctuations:
Temperature fluctuations affect tire pressure significantly. As temperature decreases, tire pressure may decrease, causing under-inflation. Conversely, rising temperatures can increase tire pressure, risking over-inflation. The American Automobile Association (AAA) states that tire pressure drops by about 1 psi for every 10°F drop in temperature. Therefore, drivers should routinely check tire pressure during seasonal changes.
Tire Age and Wear:
Tire age and wear refer to how long a tire has been in use and its overall condition. Tires typically degrade over time and may develop cracks or punctures. The Tire Industry Association recommends replacing tires every six years, regardless of tread wear. A study by the National Safety Council found that older tires lead to a higher incidence of flats and blowouts due to decreased structural integrity.
Road Conditions:
Road conditions play a significant role in influencing tire flats. Potholes, debris, and rough surfaces can puncture or damage tires. According to a report by the Asphalt Institute, poor road conditions increase the risk of tire damage significantly, especially in urban areas.

Understanding these factors helps drivers maintain tire pressure properly and reduce the risk of flat tires. Regular maintenance, including pressure checks and inspections, is recommended for safe driving.

How Can Environmental Elements Contribute to Tire Damage in Inactive Cars?

Environmental elements can significantly contribute to tire damage in inactive cars through factors such as exposure to sunlight, fluctuating temperatures, humidity, and contact with corrosive materials. Each of these factors affects tire integrity and performance.

Exposure to sunlight: Ultraviolet (UV) rays from the sun can degrade rubber compounds in tires. A study conducted by the American Chemical Society in 2017 highlights that prolonged UV exposure can lead to dry rot, cracking, and loss of elasticity in tires.
Fluctuating temperatures: Extreme temperature variations can cause the rubber to expand and contract. According to the Tire Industry Association (TIA) study from 2020, this constant stress can weaken the tire structure over time.
Humidity: High humidity levels can lead to mold and mildew development, particularly on tires that sit unused for extended periods. The Tire Technology International journal noted in 2019 that moisture accumulation can accelerate tire deterioration.
Contact with corrosive materials: Tires can come into contact with substances like gasoline, oil, and salt, which can cause chemical reactions detrimental to rubber compounds. Research from the Rubber and Plastics News in 2021 showed that such interactions lead to surface wear and potential failures in inactive vehicles.

Understanding these factors can help car owners take preventive measures to protect their tires, ensuring better longevity and safety when their vehicles are inactive for extended periods.

In What Ways Does Sunlight Affect Tires That Are Not in Use?

Sunlight affects unused tires in several ways. First, ultraviolet (UV) rays from sunlight cause degradation of the tire’s rubber. This degradation occurs because UV rays break down the chemical bonds in the rubber material. As the rubber deteriorates, it becomes brittle and cracks.

Second, exposure to heat from sunlight increases the internal temperature of the tires. This heat can lead to accelerated wear and tear. Over time, the tires may lose their pliability, resulting in a reduced ability to grip the road effectively.

Third, prolonged exposure to sunlight can cause color fading. Tires often lose their original black color and may turn gray or white. This change is mainly cosmetic, but it indicates material degradation.

Finally, without proper shelter, tires may also accumulate dust and debris. This accumulation can lead to uneven wear patterns when the tires are eventually used.

In summary, sunlight affects unused tires by causing rubber degradation, increasing internal heat, fading colors, and allowing debris accumulation. These factors combined can significantly impact the performance and longevity of tires over time.

How Do Temperature Fluctuations Impact Tire Durability?

Temperature fluctuations can significantly impact tire durability by affecting tire materials, performance, and maintenance requirements. Understanding these effects can help vehicle owners maintain their tires more effectively.

Material Degradation: Tires are made from rubber compounds that can harden in cold temperatures and soften in heat. A study by Lee et al. (2019) found that extreme cold can reduce tire flexibility, leading to cracks and decreased grip. Conversely, high temperatures can cause the rubber to wear out faster, resulting in a shorter lifespan.
Inflation Pressure Changes: Tire pressure is sensitive to temperature changes. According to the National Highway Traffic Safety Administration (NHTSA), tire pressure decreases by about 1 psi for every 10°F drop in temperature. Under-inflated tires can increase rolling resistance and reduce fuel efficiency, while over-inflated tires can lead to a higher risk of blowouts.
Performance and Handling: Temperature affects how tires perform on the road. Warm tires tend to provide better traction and handling. A report by the Tire Industry Association (2020) indicated that tires should reach their optimal temperature to enhance performance. However, excessive heat can also lead to tire separation or tread wear if the tires are not properly maintained.
Maintenance Requirements: Fluctuating temperatures can prompt more frequent maintenance checks. Regular inspections are crucial to catch issues early. The Rubber Manufacturers Association recommends checking your tire pressure every month and inspecting them for cracks, uneven wear, and bulges, especially after significant temperature changes.

In conclusion, temperature fluctuations can harm tire durability through material degradation, changes in inflation pressure, impacts on performance, and increased maintenance needs. Vehicle owners should remain vigilant, especially during seasonal transitions, to ensure their tires remain safe and durable.

What Tire Maintenance Practices Can Prevent Flat Tires for Cars That Sit?

To prevent flat tires for cars that sit, regular tire maintenance practices are essential. These practices help maintain tire pressure and overall tire health, reducing the risk of flats.

Regularly check and maintain tire pressure.
Rotate tires periodically.
Inspect tires for cracks or wear.
Store cars in a climate-controlled environment.
Use tire protection products.
Avoid prolonged contact with sunlight or extreme temperatures.

Effective tire maintenance is not just about individual practices but integrating a comprehensive approach to ensure the longevity of your tires.

Regularly Check and Maintain Tire Pressure: Regularly checking and maintaining tire pressure is crucial. Tires naturally lose air over time, especially in stationary vehicles. Under-inflated tires can cause sidewall damage and lead to flats. According to the NHTSA, about 1 in 4 cars on the road have under-inflated tires. Maintaining tire pressure at manufacturer’s recommendations can significantly reduce the risk of flats.
Rotate Tires Periodically: Rotating tires periodically helps ensure even wear. Uneven wear can lead to weak spots and blowouts. Most experts recommend rotating tires every 6,000 to 8,000 miles or during oil changes. This practice extends tire life and enhances safety.
Inspect Tires for Cracks or Wear: It is important to inspect tires for visible cracks, bulges, or uneven wear. These signs indicate potential problems, which, if addressed promptly, can prevent flats. Tire manufacturers like Michelin suggest visual inspections every month.
Store Cars in a Climate-Controlled Environment: Storing cars in a climate-controlled environment limits exposure to extreme temperatures and humidity. Both can degrade tire materials over time. Research suggests that consistent temperature conditions promote tire longevity.
Use Tire Protection Products: Tire protection products, such as sealants or covers, can shield tires from environmental damage. Sealants help seal small punctures, and covers can protect tires from UV rays. According to industry reports, these products can extend tire life by up to 30%.
Avoid Prolonged Contact with Sunlight or Extreme Temperatures: Prolonged exposure to sunlight or extreme temperatures can degrade tire rubber. Parking in shaded areas or using tire covers can significantly mitigate these risks. Studies show that tires can lose 50% of their life due to UV exposure and temperature extremes.

Implementing these practices contributes to tire longevity and helps prevent flats for vehicles that are not frequently used.

How Frequently Should Tires Be Inspected for Cars Left Parked?

You should inspect tires of parked cars at least once a month. This regular check helps identify issues such as low tire pressure, uneven wear, or visible damage. Low tire pressure can occur due to temperature changes or slow leaks. Uneven wear indicates potential alignment problems or improper inflation. Visible damage could include cuts or bulges that can lead to tire failure. By inspecting monthly, you can ensure the tires remain in good condition. Additionally, before long trips or extended periods of parking, perform a thorough inspection. This practice promotes safety and extends tire life.

What Additional Maintenance Tips Can Help Preserve Tires During Inactivity?

To preserve tires during inactivity, certain maintenance tips are essential. Proper care can prevent flat spots, premature aging, and deterioration.

Here are key tips for preserving tires during inactivity:
1. Inflate tires to the recommended pressure.
2. Elevate the vehicle to avoid flat spots.
3. Use tire covers to protect against UV damage.
4. Store tires in a cool, dry place.
5. Rotate tires periodically if possible.
6. Avoid placing heavy objects on tires during storage.

To better understand the best practices for tire maintenance, let’s delve into each point in detail.

Inflate Tires to the Recommended Pressure: Maintaining the correct tire pressure is critical. Under-inflated tires can develop flat spots and lead to structural damage. The recommended pressure can usually be found on a sticker inside the driver’s door or in the vehicle’s manual. According to the National Highway Traffic Safety Administration (NHTSA), maintaining proper tire pressure improves fuel efficiency and extends tire life.
Elevate the Vehicle to Avoid Flat Spots: Elevating the vehicle reduces the risk of flat spots forming. Flat spots occur when the same area of the tire remains in contact with the ground for extended periods. Using jack stands or ramps can effectively lift the vehicle during storage. A study from Tire Review highlights that even a short period on a flat surface can negatively impact tire integrity.
Use Tire Covers to Protect Against UV Damage: Tire covers shield tires from harmful ultraviolet (UV) rays. Extended exposure to sunlight can cause the rubber to dry out and crack. Recommended by manufacturers, tire covers are an effective solution to extend tire life. The Rubber Manufacturers Association notes that UV degradation is a significant factor in tire aging.
Store Tires in a Cool, Dry Place: Tire storage conditions matter greatly. Storing tires in a climate-controlled environment helps prevent moisture accumulation that can lead to mold and deterioration. Keeping them away from heat sources and direct sunlight is crucial. According to a report by Consumer Reports, ideal storage conditions can increase tire lifespan significantly.
Rotate Tires Periodically if Possible: If the vehicle remains inactive for a long period, rotating the tires can help minimize flat spots. By changing their position occasionally, tires wear uniformly. The Tire Industry Association recommends rotating tires every 5,000 to 7,500 miles for optimal performance, which can also be applied during storage.
Avoid Placing Heavy Objects on Tires During Storage: Placing heavy objects on tires can deform them over time. This pressure may cause permanent changes in tire shape, rendering them unusable. The National Tire Dealers Association advises against this practice to preserve tire structure and elasticity.

Implementing these maintenance tips can promote longevity and performance in tires during inactivity. Following these guidelines helps vehicle owners ensure their tires remain in excellent condition when the time comes for use again.

What Are the Consequences of Neglecting Tire Maintenance on Inactive Vehicles?

Neglecting tire maintenance on inactive vehicles can lead to multiple detrimental consequences, including tire degradation, flat tires, and safety hazards.

Tire Degradation
Flat Tires
Safety Hazards
Financial Costs
Environmental Impact

Neglecting tire maintenance can have significant repercussions. Each of these consequences warrants a detailed explanation to understand the full extent of the issue.

Tire Degradation: Tire degradation refers to the deterioration of tire quality over time due to exposure to environmental elements. When a vehicle remains inactive, tires can develop flat spots where they contact the ground. These spots become rigid and can lead to uneven wear. According to the Rubber Manufacturers Association, tires can begin to degrade after six months of inactivity due to the chemical breakdown of rubber.
Flat Tires: Flat tires occur when the air pressure inside a tire drops significantly. This drop can result from leaks or prolonged pressure loss while the vehicle is stationary. Inactive tires may lose air due to natural evaporation through the rubber, which can lead to a complete flat if left unmonitored. A study from the National Highway Traffic Safety Administration indicates that under-inflated tires can contribute to poor vehicle handling and increased chances of tire blowouts.
Safety Hazards: Safety hazards increase when neglected tires are eventually used. Deterioration and flat tires can compromise traction, handling, and braking efficiency. The National Safety Council warns that driving on poor tires can significantly elevate the risk of accidents. Tires that have been inactive for extended periods may also fail to adhere to road surfaces, risking driver safety.
Financial Costs: Financial costs accrue from both the need to replace damaged tires and potential vehicle repairs due to tire-related accidents. Neglecting tire maintenance can lead to advanced damage that could have been avoided with regular checks. According to Consumer Reports, the total cost of ownership can rise significantly if tire replacements and repairs are neglected over time.
Environmental Impact: Environmental impact arises from an increased number of waste tires sent to landfills due to negligence. Degradation in tire quality leads to disposal issues, contributing to environmental pollution. In fact, the U.S. generates about 290 million scrap tires each year, as reported by the U.S. Environmental Protection Agency. Proper maintenance and recycling programs can mitigate this impact.

In summary, the consequences of neglecting tire maintenance on inactive vehicles are severe. Proper tire care is essential to prevent degradation, flat tires, safety hazards, financial costs, and environmental issues. Regular checks and maintenance can prolong tire life and ensure both safety and cost-effectiveness.

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Why Do Cars That Sit Get Flat Tires? Effects of Duration and Tire Maintenance