Since the 1970’s the Anti-Lock Braking system, now almost ubiquitous, has been helping drivers retain control during heavy braking on wet or slippery roads. The wheel rotation sensors, at the heart of ABS, have been co-opted into traction and stability control systems. Drivers do not consciously rely on these systems to save them from a mistake but seasoned drivers (code of older people) will have noticed that they appear to be much better drivers now than when they were in their 20’s. Which is surprising as reaction times increase with age.

What has been happening over the last thirty years is that vehicle safety systems have become more intelligent and tyres have more grip resulting in minor driver errors being recoverable by a combination of driver input, ABS, ESC and ATC. This list of potentially lifesaving innovations will soon include ‘look-ahead systems’ preventing us from tailgating the car in front or straying out of our motorway lane. None of these worthwhile advances has relied upon sensors embedded in the tyre because such sensors were not needed. Will embedded tyre sensors be capable of delivering worthwhile improvements to safety and/or vehicle dynamics without causing service and support problems for vehicle owners.

Quiet tyres

To develop tyres that run more quietly, with better grip and with lower rolling resistance knowledge of what is happening to the tyre as inputs change is vitally important. There will always be a need for tyre sensors that can provide real operating data that supports the predictions made by the analytic tyre models that are increasingly at the centre of our tyre development. Bay Systems responded to this need in 2006 by developing the Tyre Cavity Microphone (TCM) and other measurement modules that are used to study the behaviour of tyres in the laboratory and more importantly on the road, the environment where they are used. When comparing laboratory and road measurement it was clear that road data contains random variations not seen in the laboratory, see figures 1a & b.

The sound pressure level (SPL) inside a tyre is usually dominated by cavity resonance modes, the primary mode being strongest. The rms level of the noise inside the tyre’s cavity, at any given speed, responds to the texture of the road surface, the coarser the texture the higher the rms level. With a little signal processing the signal from the TCM’s microphone can be processed to give an indication of the road surface condition as can the signal from the TCA’s accelerometer mounted or embedded in the tyre liner, see figures 2 a & b.

The microphone positioned on the rim and integrated into the TPMS housing is potentially in a much safer location than a sensor buried in the tyre’s structure. Tyre fitters are used to remove and install TPMS modules making maintenance easier and more affordable than repairing sensors buried in a tyre’s structure. Inevitably sensors and systems will fail and any sensor mounted in the tyre is destined to have a stressful life. Tyre liner temperatures can exceed 120 degrees C depending on; speed, ambient temperatures and tyre type. Elevated temperatures (>50 degrees C) degrade batteries and semi-conductors. Most semi-conductors fail or suffer dramatically shorter service lives if their ambient temperature regularly reaches 80-100-degree C.

For many drivers the prospect of warning lights burning on their dashboards due to tyre mounted transducers failing will be very unwelcome, particularly if the recommended cure is to buy a new tyre. If the only way to pass the annual vehicle inspection, common in many countries, is for the tyre safety system to be working or not fitted then the not fitted option will be preferred by most buyers of used vehicles. If SMART wheel sensors can be shown to deliver genuine benefits then integrating them into a rim mounted package might be the lowest risk approach, at least from the customer’s perception.

Universal TMS

A Universal Tyre Monitoring System (UTMS) package would therefore appear to be the most attractive option in terms of convenience and minimising the costs associated with maintenance and repair. Essentially the Bay Systems’ TCM system is a UTMS system, albeit for R&D use only. The key question is therefore; ‘Can the data from UTMS be usefully employed to enhance vehicle utility, handling and safety?’ This is a difficult question to answer, for handling and safety, as for these applications the chassis management system (CMS) computer must receive and process signals in real time for the information to be usefully employed. Being informed that road surface icing has occurred some 30 metres after the vehicle has transitioned onto ice is liable to be too late. The signal from a tread liner accelerometer, see figures 3a. shows the transition from wet to flooded road, N.B. the vehicle was not aquaplaning but a slight increase in speed might well have invoked it. This raw time history would need to be processed before it could be used to trigger an intervention, in figure 3b a wavelet transform is used to highlight the differences between wet and flooded road surfaces. Real time responses imply high data rates from sensors, which in turn result in higher power consumption. Getting power to and signals back from the two front wheel sensors, rear wheel road surface information is typically front wheel data delayed by 3 metres, or from all wheels will be a challenge. Vehicles may be parked for days and even weeks, UTMS must shut down completely to conserve battery life. This may be achieved using a motion switch, these are readily available but as always adding complexity increases the risk of failures. The bigger problem is how to maintain and recharge the battery during normal usage. Any form of physical coupling through a connector will certainly be damaged or fail through water ingress making some type of induction coupled charging a more attractive option.

Low power radio transmission has worked well for TCM. However, such a system across the entire vehicle fleet may present problems on densely trafficked roads. On a busy motorway a vehicle might pass within 2 metres of another vehicle at a rate of 10 per second. Should all of these vehicles be using the UTMS radio spectrum then there will be up to 40 channel contentions per second to resolve. It is unlikely that radio spectrum will be made available that allows space for more than 100 channels. Each vehicle’s UTMS radio system must be primed to channel hop to avoid contentions from up to 10 interfering vehicles per second while sustaining a minimum data rate of 100kbytes per second.

Such a work load imposed be an ever-changing mix of vehicles will be difficult to manage without gaps in the data. A possible solution exists if the transmitted power from UTMS is very low, to the point that signals are only detectable inside the transmitting vehicle’s own wheel arch. Very low power radio transmission also brings low power drain at the transmitter making power supply easier. However, it also implies that a high receiver sensitivity might be needed. The extremely weak signals from nearby vehicles may therefore become detectable which returns us to the problem of radio channel contentions. Setting a low transmission power limit is therefore likely to be an area of diminishing returns and the channel contention issue is likely to always exist for high data rates.

To calculate the instantaneous rolling resistance of each wheel the CMS will require only two measurements; the temperature of the tyre and its pressure. A once per second reading rate for these two parameters would be enough, due to the tyre’s relatively high thermal inertia and

the normally slow rate of change of inflation pressure. The liner temperature measurement might be over a single area or across a section of the tyre. In the case of our TCT system (aimed at tyre R&D) the measurement is over 64 pixels and can stretch from bead to bead or be focused on an area if interest e.g. the tyre’s shoulder with an accuracy of 0.1 degrees C and resolution of 0.01 degrees C. A measurement cycle, even at high resolution would require a data packet of less than 200 bytes which with overhead might be 1kbytes. This rate would fit into the radio channels even on a busy motorway making dynamic estimation of rolling resistance possible while real time road surface measurement would be problematic.

Rolling resistance can account for up to 30% of battery energy in an EV making the choice of tire and the way the vehicle is driven very important; potentially being the difference between driving and walking the last few miles home on a cold wet night! There will be, for any journey, an optimum vehicle speed and route where energy consumption will be minimized. The probability of reaching the destination will be increased if this route is followed but it is more important to alert the driver if there is a significant probability of not reaching the destination on the remaining battery charge.

EVs with batteries that are over three years old may have battery capacities of 80% or less of the new capacity. This makes a planned journey of just 100miles (160km) problematic, particularly when air conditioning, heater and windscreen wipers are all operating. This range deficit may increase with traffic conditions such as road works, detours, accidents etc. To increase driver confidence a fully integrated vehicle management and GPS route planning system would need to use environmental data such as ambient temperature, wind speed and direction together with vehicle data such as load and UTMS derived tyre liner temperature and pressure to calculate the projected energy consumption for any proposed route. For this total tyre energy budget to be calculated for the journey the full tyre specification will be needed for each tyre i.e. the rolling efficiency for all temperatures, inflation pressures, loads and temperatures. The GPS navigation system, using these parameters and taking into account traffic updates would then evaluate the probability of reaching the destination without a battery recharge. If the journey was beyond the battery range an alternative route would be suggested that would pass a recharging station.

Data accuracy

The key to all this working reliably will be the accuracy of the tyre specification data entered into the CMS. What will be needed will be the full energy dissipation profile for all conditions, not just the laboratory performance rating, though this would be better than nothing. Tyres are currently rated for energy dissipation (rolling resistance) when operating in a laboratory at 25 +/- 4 degrees C while running on a smooth steel road wheel. The tyre is run for 30 minutes at 80kph before the test, is correctly inflated and is carrying 80% of its maximum load. Our measurements have revealed that the liner temperature across similar tyres from different manufacturers can vary from 50 to 90 degrees C for this test.

Energy dissipation drives the liner temperature higher until thermal equilibrium is reached. On the road, in the real world, the maximum temperature measured on the liner of a Mazda BT50 pickup truck tyre was 45 degrees C when pulling a trailer at a steady 100kph for 6 hours with an air ambient temperature of 22 degrees C. i.e. much lower than would have been expected. Energy efficiency improves with increasing temperature at the rate of 0.6% per degree C, over the temperature range 15-50 degrees C. It is highly likely that most tyres operating in temperate regions are not delivering their labeled energy efficiencies because they are running cool. This applies even in the summer when ambient temperatures are near those specified for the laboratory. In the winter the Mazda truck tyre did not reach 30 degrees C. i.e. half of the lab test result and probably 2 full tyre grades worse performance than the label states, possibly resulting in a 5+ mile shortfall in vehicle range.

While the case for in tyre sensors and even rim-based sensor fitment to vehicles is open to debate the case for their use in R&D is now well proven and accepted. Tyre internal noise and tyre cavity resonance is easily and reliably measured with good accuracy, both on a laboratory road wheel and on the highway. The differences between tyres from different manufacturers can be quickly evaluated, see figures 4 a & 4b, allowing car makers to choose a tyre best suited to their vehicle and the road surfaces it is most likely to be driven over. For the tyre companies their new product development can be steered towards lower levels of noise and cavity resonant modes.

The primary cavity resonance mode if heard in the vehicle cabin is annoying and is often interpreted by the owner as a defect. For auto makers noise complaints are a concern as investigation in the field is costly and if unresolved becomes a barrier to a repeat sale. Tyre companies are encouraged by auto makers to reduce cavity resonant mode levels and reduce road noise. The loss of vehicle control is a much more serious matter and has always been at the top of the priority list for tyre and auto companies. The measurement of tyre liner acceleration provides a great deal of information including early warning that the threshold for aquaplaning is imminent, see figure 3a.

Reductions in pre and post contact patch waves, see them clearly in figure 5, that propagate around the tyre will lead to reductions in radiated noise and lower pass-by noise levels. No improvement in a tyre’s characteristic comes free of charge and this cost is often a trade off with other equally desirable characteristics. Typically, less grip and faster wear rates are what result when a tyre’s energy dissipation is improved. Wet grip performance is featured on the tyre label and who would deliberately choose a tyre with lower wet grip. Leaving the most likely trade off candidate as wear and of course faster wear means more particulates shed into the environment which is undesirable. It seems likely that wear rate will soon appear on the tyre label. There seem to be no unalloyed successes, only the least worst choices to be made!

Eurogrip Tyres, the leading tyre manufacturer in India, showcased its premium two-wheeler tyres at the 17th edition of Feria 2 Ruedas (F2R) International Motorcycle exhibition held at Plaza Mayor, Medellin, Colombia. The dates of this high-profile business event in South America's two-wheeler sector are 15–18 May 2025.

For more than 17 years, the Feria de las 2 Ruedas (F2R) has been the leading motorcycle industry event in Latin America. The expo, which takes place every year in Medellín, Colombia, is a vibrant venue for commerce, innovation and growth in the motorcycling sector. Additionally, it gives aficionados the chance to investigate the most recent developments and trends in the industry. The company showcased its premium lineup at exhibit N24 in the Tented Pavillion, which included a range of sport touring, off-road and trail tyres. High-performance versions including the Roadhound, Protorq Extreme, Trailhound STR, Climber, Bee Connect, Terrabite DB+ and Badhshah LX were on display.

P Madhavan, Executive Vice-President – Marketing & Sales, TVS Srichakra Ltd, said, “Eurogrip is focused to deliver innovative products for the global markets. Latin America is a priority market for us, and F2R Expo is a promising platform to engage with our target audience. We are looking forward to interesting business opportunities arising from this expo. Such specialised industry tradeshows add exceptional value to our quest in becoming a leading global tyre brand delivering world class tyre technology.”

Denka Company Limited announced it would record an extraordinary loss of approximately 16.1 billion yen (£85.8 million) as an impairment on manufacturing facilities at its US subsidiary. It will indefinitely suspend chloroprene rubber production at the Louisiana plant.

The Japanese chemical manufacturer, which holds a 70 percent stake in Denka Performance Elastomer LLC (DPE), cited mounting operational challenges, including unexpectedly high costs for pollution control equipment and declining production volumes at the American facility.

“DPE has faced significant cost, production and other challenges at its facility in the United States,” the company said in a statement. “Rising costs are attributable to, among other factors, identification, design, purchase, installation, and operation of pollution control equipment to reduce chloroprene emissions that DPE did not anticipate being required when it acquired the facility from E.I. DuPont de Nemours and Company.”

The subsidiary was established in December 2014 and acquired the chloroprene rubber business from DuPont in November 2015. The Louisiana facility was intended to serve as a second manufacturing site in North America, complementing Denka’s Omi Plant in Itoigawa, Niigata, Japan.

However, according to the company statement, DPE has struggled with multiple operational issues, including “rising energy costs and a shortage of qualified staff necessary to operate new pollution control equipment and implement other emission reduction measures. “

Production volumes have declined partly due to “operational restrictions arising from the pollution reduction measures and unscheduled plant outages associated with supply chain disruptions and severe weather events,” Denka said.

The company noted that these challenges, combined with changes in the global economic environment for chloroprene rubber, have pressured profitability, making near-term improvement difficult.

Denka confirmed that DPE employs 250 people as of December 2024 and will not restart its chloroprene rubber manufacturing facilities following a regular maintenance shutdown. Instead, “all options for the business, including a potential sale of the business or its assets, will be considered,” the statement said.

The company emphasised that “no decision regarding a permanent closure of the facility has been made at this time.”

Customers will continue to be supplied from current inventories and production at the company’s Omi Plant in Japan.

DPE is 70 percent owned by Denka USA LLC, a wholly owned subsidiary of Denka Company Limited, and 30 percent by Diana Elastomers, Inc., a subsidiary of Mitsui & Co., Ltd.

Yokohama Rubber reported a 56.9 percent year-on-year decline in profit attributable to owners for the first quarter of 2025, despite posting a 9.0 percent increase in sales revenue.

The Japanese tyre maker recorded a profit of 8.53 billion yen for the three months ended 31 March, down from 19.8 billion yen in the same period last year. Business profit fell 3.2 percent to 24.07 billion yen, while sales revenue rose to 275.12 billion yen.

The company maintained its full-year forecast, projecting an 11.4 percent increase in sales revenue to 1.22 trillion yen and an 8.8 percent rise in profit to 81.5 billion yen for the fiscal year ending 31 December 2025.

Yokohama Rubber attributed the profit decline to one-time costs related to its February acquisition of Goodyear’s off-the-road (OTR) tyre business, which it purchased for approximately 143 billion yen.

“Profit from existing businesses was strong,” the company said in its earnings statement. “In addition to increased sales volume for the company’s consumer tyres, mainly in overseas markets, and continued expansion of sales of high-value-added ADVAN, GEOLANDAR, and Winter tyres as well as high-inch tyres, profit was boosted by the MB segment’s MIX improvements and structural reforms.”

The tyre segment, which accounts for 91percent of the group’s consolidated sales revenue, saw a 10.4 percent increase in sales to 250.32 billion yen. Original equipment tyre sales were higher year-on-year, driven by “strong sales in Japan of vehicle models equipped with YOKOHAMA tyres and expansion of shipments for Chinese automakers’ new energy vehicles,” the company said.

Replacement tyre sales also increased, supported by higher sales of summer and winter tyres in Japan, increased sales of high-inch tyres in Europe, and stepped-up sales efforts in Asia.

The MB (Multiple Businesses) segment, which represents 8.4 percent of total sales, experienced a 3.2 percent revenue decline to 23.02 billion yen. This was attributed to lower demand from construction machinery makers in Japan and automakers in North America.

The company described an “upbeat” business sentiment in Japan for the quarter, noting that “a steady recovery in inbound demand and increasing orders for construction and logistics projects compensated for weak consumption by domestic households curbing spending in response to rising prices of consumer goods.”

Overseas, the company observed rising inflation concerns weighing on consumer spending in the United States, while in Europe, “manufacturing industries are rebounding and corporate business sentiment is improving.” In China, personal consumption was boosted by the Spring Festival holiday, but high US tariffs “reduced China’s exports and created uncertainty about the future that is weakening industrial activity.”

Swedish speciality chemicals firm Nynas reported solid financial results for 2024, posting an Adjusted EBITDA of 1,333 million Swedish kronor, marginally higher than the 1,316 million kronor recorded in 2023.

The company, which specialises in naphthenic speciality oils and bitumen products, attributed its performance to operational efficiency and commercial success in its niche markets.

“We are delighted with the progress made during 2024, evidencing our right-sized cost base and a more targeted commercial and manufacturing footprint. We have redefined our strategic direction, positioning Nynas as a speciality chemicals company, enabling the energy transition and setting our course for 2035,” Nynas CEO Eric Gosse said in a statement.

The firm highlighted strong cash generation from operations, which it said would support planned investments and longer-term growth initiatives. Nynas also mentioned the ongoing transformation of its Harburg site with plans to monetise the asset eventually.

All three of the company’s production facilities maintained high operational reliability between 95 percent and 99 percent. The Nynäshamn refinery achieved a notable milestone: in May 2024, it set a new monthly production record for naphthenic speciality oils at 42,000 tonnes.

Strategic pivot towards sustainability

Nynas outlined a strategic shift focused on higher-margin speciality materials with sustainable characteristics. The company aims to strengthen its position in European markets through innovation and sustainability initiatives.

“Nynas is uniquely positioned to contribute to the energy transition. Our strategy reflects our purpose to advance a more sustainable society, and our product development pipeline is fully aligned with this goal," Gosse added.

In 2024, the company received an EcoVadis Gold rating, placing it in the top 5 percent of globally rated businesses for sustainability performance.

With consecutive years of strong financial performance, Nynas indicated it continues to monitor debt capital markets to optimise its capital structure “at the appropriate time potentially”.

The Swedish chemicals producer noted that, having ceased operations in the United States in 2022, it remains largely insulated from recent global trade tensions surrounding US import tariffs. The company imports only minimal feedstock from America, shielding it from potential cross-border trade disputes.