Everything You Need To Know About Electric Car Tires

Summary

This video, sponsored by Hankook, delves into the unique challenges of designing tires for electric vehicles (EVs), which are heavier, quieter, and have high torque. The script explains how increased tire stiffness and specific compounds address weight and wear issues, while rolling resistance is crucial for EV efficiency, impacting range significantly more than in gas cars. Noise reduction techniques, such as polyurethane foam inserts and multi-pitch sequencing, are highlighted to ensure a quiet ride. The video emphasizes the importance of tire design in maximizing performance and range for EVs.

Takeaways

• 🚗 Electric vehicles (EVs) are heavier than their gas counterparts, often by 20-30%, due to the weight of the batteries needed for range.
• 🔩 The extra weight of EVs puts more pressure on the tires, leading to increased wear, with EV tires wearing about 20% faster compared to those on lighter combustion cars.
• 💪 To handle the weight and improve steering response, EV tires are designed with increased stiffness, such as 25% higher lateral stiffness and 20% higher quartering stiffness.
• 🔄 EV tires use a stiffer compound to reduce wear from the higher weight and have a flatter contact patch to spread the load and improve wear distribution.
• 🛣️ Rolling resistance is crucial for EVs due to their high efficiency; a lower coefficient of rolling resistance can significantly impact the range of the vehicle.
• ⚖️ A simple tire choice can affect the range of an EV by up to 30 miles, whereas in gas cars, the impact is much less noticeable due to larger fuel tanks.
• 🔬 Hankook improves rolling resistance through advanced tire compounds and even curing processes, which can result in up to a 10% difference in performance.
• 🚫 Electric cars are much quieter than gas cars, making noise reduction in tires especially important to prevent tire and wind noise from becoming more noticeable.
• 🎚️ Noise reduction features in EV tires include sound absorbers, zigzag patterns in the tread to suppress resonance, and expanding lateral grooves to minimize noise breakout.
• 🔊 Multi-pitch sequencing in tire tread design helps to reduce overall noise by preventing a consistent rhythmic pattern that can generate noise when hitting the road surface.
• 🌀 The immediate and high torque delivery of EVs requires tires with enhanced grip and rigid internal construction, such as jointless belts and aramid belts, to handle the forces without deforming.
• 🏆 Hankook's ion tire lineup is designed to meet the specific challenges of EVs, with high ratings for rolling resistance, wet grip, noise, and durability.

Q & A

Why are electric car tires different from regular tires?

Electric car tires are different because they need to address specific challenges such as the weight of electric vehicles (EVs), their high efficiency, quiet operation, and significant torque. These factors require specialized tire designs for better performance and longevity.

Why are EVs generally heavier than traditional gas cars?

EVs are heavier due to the substantial weight of their batteries needed for achieving desired ranges. For instance, a 300-mile range might require around 1000 pounds of battery weight compared to about 70 pounds of fuel for a gas car.

How does the weight of an EV affect tire wear?

The increased weight of EVs puts more pressure on the tires, resulting in faster wear. According to Hankook's testing, the same tire on an EV will wear about 20% faster compared to a lighter combustion car.

What modifications are made to the tire's structure to handle the weight of EVs?

To handle the weight, the stiffness of the tire is increased. For example, Hankook's EV tire has 25% higher lateral stiffness and 20% higher quartering stiffness compared to their standard SUV touring tire.

How does tire stiffness affect steering response and comfort?

Increased tire stiffness improves steering response by reducing the tire's lateral stretch when turning, thus eliminating 'slop'. However, on a lightweight combustion car, the same stiff tire might compromise comfort due to a stiffer ride.

What role does tire compound play in reducing wear for EVs?

EV tires use a stiffer compound to reduce wear impact caused by the higher weight of the vehicles. This compound, combined with a flatter contact patch, helps spread the load and improve wear performance.

Why is rolling resistance critical for the efficiency and range of EVs?

Rolling resistance is the energy lost as heat when the tire deforms while moving. For EVs, which are highly efficient, even small changes in rolling resistance can significantly impact range. A tire with higher rolling resistance can cause an EV to use up to an additional eight kilowatt-hours of energy over 200 miles.

How does Hankook improve the coefficient of rolling resistance in their EV tires?

Hankook improves the coefficient of rolling resistance through advanced tire compounds and vulcanization processes. Even pressure distribution across the contact patch and a uniform curing process can lead to better rolling resistance properties.

What is the impact of noise on the driving experience in electric cars?

In electric cars, which are much quieter than combustion engines, any noise, including tire noise, becomes more noticeable. This heightened sensitivity to noise requires special tire designs to reduce noise levels inside the cabin.

What features does Hankook incorporate in their tires to reduce noise?

Hankook uses features such as a polyurethane foam insert to dampen resonant vibrations, zigzag patterns in the water channels to suppress resonance, expanding lateral grooves to minimize noise breakout, and multi-pitch sequencing to avoid rhythmic noise generation.

How does the immediate torque delivery in EVs affect tire performance?

The immediate and high torque delivery in EVs can cause wheel spin if the tires do not have sufficient grip. Therefore, the tire's construction and compound must be rigid enough to handle the torque and the vehicle's weight, especially for performance EVs.

What are the specific ratings and warranty for Hankook's Ion All Season tire?

The Ion All Season tire has a UTQG rating of 600 for wear, an 'A' for wet grip, and an 'A' for temperature rating. It comes with a 50,000-mile warranty, indicating long-lasting performance with good wet grip and durability.