Why does an electric vehicle need different tyres than a vehicle with combustion engine?
Compared to a conventional tyre, tyres for EVs (electric vehicles) must meet four specific requirements:
- They have to offer a particularly low rolling resistance so that the vehicle can travel as far as possible with one battery charge.
- They should add to the high degree of noise comfort offered by electric cars (thus be as quiet as possible).
- They need to be designed to handle very high torques from standstill without generating excessive wear.
- They have to be designed to suit the higher vehicle masses of electric cars, due to the heavy electric vehicle batteries.
Tyres in the Hankook iON family score top marks in all categories.
How does Hankook achieve these product properties?
One factor for the improvement in rolling resistance is due to the weight savings of up to one kilogram per tyre. This is achieved using plant-based oils, which ensure less abrasion; less material is therefore required on the tread to achieve the same mileage. These oils are also more environmentally friendly. Aerodynamic optimisation also ensures a greater range per battery charge. The tyre pattern is therefore designed in such a way that air resistance is also reduced. This even applies to the lettering on the tyre sidewalls.
In addition, the tread mixture on the iON series also has a huge impact on the rolling resistance: highly dispersible polymers, a high proportion of silica and a modern mixing process all result in greater tread elasticity, while also reducing unnecessary movement in the tread. This reduces energy loss and thus rolling resistance. A test performed by TÜV SÜD1 shows that the Hankook iON evo – fitted on popular premium electric vehicles – is clearly superior to conventional tyres, especially in terms of rolling resistance.
Hankook i Sound Absorber technology and the design of the tyre pattern are the main factors in achieving a particularly low noise level. This is especially important for electric vehicles, since there is no combustion engine to produce noise, meaning other sources of noise are noticed even more clearly. The Hankook iON evo was the quietest tyre in the TÜV Süd test.
Hankook iON tyres are specifically designed for the high torques of electric vehicles. It is possible to accelerate from a standstill with reduced wheel slip and thus less abrasion – the tyre provides the necessary grip. The tread mixture contains a high proportion of natural resin, which ensures exemplary durability and reduced abrasion.
Finally, Hankook has addressed the larger vehicle mass of electric vehicles with a load distribution that is adapted to higher load capacity over the entire width of the tread. Lasting stability is made possible with the extra-resistant aramid fibres, which effectively counteract deformation.
Does low rolling resistance as a primary development goal not conflict with other, safety-related development goals?
Safety is the top priority for road vehicles – there must be no compromise in this regard.
With the iON, the Hankook engineers have brilliantly solved the conflict between minimising rolling resistance while maintaining the same qualities in other important criteria such as handling and wet braking performance, as the TÜV SÜD test proves. Fitted on popular premium electric vehicles, the Hankook iON evo was clearly superior, especially in terms of rolling resistance. At the same time, it did not deviate from competitor benchmark specifications; it even achieved top scores for wet and dry braking performance. It was also the quietest tyre in the test.
Using natural resin helps to maintain a good grip on wet surfaces, despite the low rolling resistance. Also of particular note is the high silica content of the iON, which provides micro-level grip on wet roads by counteracting the formation of a film of water between the road surface and the tyres, which can be dangerous.
In which variants does Hankook offer the new iON tyre?
The iON products are available in the following variants in sizes from 18 to 22 inches: In Europe, the Hankook iON evo summer tyre and the iON i*cept winter tyre have been available since 2022. Since 2023, the Hankook iON FlexClimate has completed the line-up with an all-season tyre. For autumn 2024, Hankook will be adding a further model to the series: the iON GT summer tyre will be available in sizes from 16 to 20 inches. In addition to the A/A/A rating on the EU tyre label, the iON GT is characterised by high sustainability and is largely made from recycled and renewable materials. This is also confirmed by the internationally recognised ISCC PLUS certification. (ISCC = International Sustainability & Carbon Certification). The new tyre is ideal for saloons, city cars and compact SUVs.
The iON tyre family is intended to help advance the energy revolution, making electromobility even more sustainable. How will this work?
Compared to standard tyres it is possible to achieve more kilometres per battery charge with the Hankook iON. This is a significant step forward in people accepting electric vehicles – and reducing a common worry about their range – as well as reducing CO2 emissions from road traffic.
In May 2024, Hankook presented the first EV summer tyre with ISCC PLUS certification with the iON evo. The new tyre is derived from the Hankook iON Race tyre, which has been used exclusively on the vehicles competing in the ABB FIA Formula E World Championship since 2023 and consists of 45 percent sustainable raw materials. The engineers used renewable and recycled materials that match the strength, flexibility and durability of conventional tyre components. These include, for example, bio-based silica from grain waste, recycled PET textile cord from plastic waste, bio-circular synthetic rubber from bio-circular raw materials, recycled carbon black from old tyres and even natural resin.
The new iON evo is original equipment for the updated Porsche Taycan electric sports car.
Further proof of Hankook’s efforts towards sustainability: The iON tyre family is produced in the company’s production plant in Rácalmás, Hungary, which has also been awarded the prestigious ISCC PLUS certification (International Sustainability & Carbon Certification) for the promotion of environmentally friendly practices.
This is testament to the company’s unyielding commitment to sustainability, innovation and environmental responsibility. The use of sustainable raw materials is further proof of how Hankook is intensifying its activities with respect to carbon neutrality and conservation of resources.
What advantages does the new all-season iON FlexClimate tyre offer?
Thanks to the latest technologies, the Hankook iON FlexClimate available since October 2023 offers outstanding performance for both summer and moderate winter road conditions. In addition to the excellent grip on wet surfaces compared to conventional tyres, the main features include the particularly low rolling resistance and the extremely robust construction optimised for weight, which is tailored specifically to the requirements of electric vehicles. The iON FlexClimate carries the M+S and 3PMSF (Three-Peak-Mountain-Snow-Flake) labels, and is therefore approved for year-round use in many parts of Europe. It also already benefits from the newly introduced “iON Innovative Technology”. The outstanding winter properties of the iON FlexClimate are also confirmed by TÜV Süd, which compared the tyre against four premium competitors in the test. All in all, the Hankook all-season tyre proved to be clearly superior in all safety-related criteria such as braking on snow, in rain and on dry surfaces.2
What does the new iON technology system include?
“iON Innovative Technology” is an innovation ecosystem developed by Hankook to provide an efficient way of incorporating R&D results into improvements in EV tyres. The system is based on around 58 patented technologies, which have been incorporated into the development of the iON tyre family.
There are four key technologies:
- i Sound Absorber (noise): Reduces cabin noise by adding a special foam lining to the inside of the tyre.
- i Super Mileage (wear): The ProDurable compound technology ensues a long tyre life thanks to an advanced material mix, thereby contributing to increased mileage. Round Even guarantees an extremely even contact pressure on the road.
- i Perfect Grip (grip): The Grip Boost technology ensures high sidewall rigidity for more driving comfort and vehicle control in conjunction with the aramid belt.
- i Extreme Lightness (rolling resistance): Hankook’s Opti Cure technology is an advanced vulcanisation technology that helps to significantly reduce rolling resistance. Thanks to this technology and a modern mixing process, the tread design reduces unnecessary tread movements. This further reduces the energy loss and thus the rolling resistance.
How does Hankook test new iON technologies?
One example of Hankook’s technology transfer in action is the iON Race – the official racing tyre of Formula E. Since 2023, Hankook has been an exclusive technology partner and tyre supplier to the ABB FIA Formula E World Championship. The development of the iON Race also benefits car drivers, since electric vehicles need tyres with greatly reduced rolling resistance for increased range, high traction even on wet roads, very good braking performance and high resilience.
Is Hankook working on expanding the tyre portfolio for electric vehicles?
The iON tyre series specifically optimised for electric vehicles is aimed at the passenger car sector, however the company is also expanding the line-up to commercial vehicles. With the e-SMART series, Hankook is introducing the first product line for electric commercial vehicles. The first product is the e-SMART City AU56, specifically for electric city buses.
1) TÜV SÜD Tire Test 2022, report no. 713252186-BM01, -PM01. Test period March 2022. Test of the Hankook iON evo with four competitor tyres, all in the dimension 245/45 ZR19 102Y XL. Test vehicles Tesla Model S 85, Tesla Model S P100D, Audi Q5 Sportback 40 TDI, VW Tiguan 2.0 TDI. Test locations: IDIADA, Papenburg, Neubiberg, Garching. Applies to all other mentions of the TÜV SÜD Tire Test
2) Source: www.hankooktire.com/uk/en/tire/ion/flexclimate.html
