What is the future for passenger car lubricants?

Today, more than 1.2 billion passenger cars dot the global roadways—and that number is only growing. Simultaneously, government bodies are becoming increasingly concerned with fighting climate change via increasingly stringent regulatory measures that are intended to curb emissions and help the world move cleaner. Collectively it means passenger vehicle technology must rapidly adapt, with significant changes anticipated in the future.

Engine technology continues to evolve, utilizing innovations that target improved fuel economy via gasoline direct injection, engine downsizing and turbocharging, all of which maximise combustion efficiency. As a result, passenger car lubricant technology has had to keep pace with these rapid engine hardware changes and today’s lubricants comprise high-performing formulations that efficiently deliver outstanding engine protection.

The Influence of COVID-19

In addition to the ongoing global drive to curb emissions, the COVID-19 pandemic has accelerated the aforementioned trends. 2020 witnessed a significant decline in new car sales, which may take years to rebound. Additionally, widespread remote working conditions, led to lower rates of private vehicle ownership. Most significantly and unexpectedly, however, was the effect of a precipitous decline in all global transportation during lockdowns, which resulted in immediate, tangible reductions in air- and water-pollution that were demonstrably experienced by humankind. This unexpectedly reinvigorated the climate change debate by citizens and politicians alike—the case for change has never been stronger with sustainable transportation being thrust to the forefront of the global stage. Government and automaker incentive programmes such as ‘cash for clunkers’ style schemes have been created to stimulate new car sales and a move toward more efficient new vehicles.

The global pandemic also led consumers to migrate from in-store purchasing to online which includes online purchase of engine oil and services for vehicle maintenance. In China, for example, pre-COVID forecasts estimated that 15% of engine oil would be sold online in 2021. The pandemic likely will have pushed those numbers even higher.

The urgent advancements in passenger car engine technology have mandated some recent and significant changes to the way that lubricants are developed, tested and marketed to consumers

Changing product technology

Meanwhile, the urgent advancements in passenger car engine technology have mandated some recent and significant changes to the way that lubricants are developed, tested and marketed to consumers. The 2020 implementation of ILSAC GF-6, the performance standard for passenger car lubricants in North America, represents such an example wherein the specification requires lubricant performance to match recent advancements in engine hardware such as gasoline direct injection (GDI) or turbocharged GDI (TGDI) engine vehicles. These GDI hardware upgrades place greater thermal stresses on the lubricant than traditional port fuel injected engines. Additionally, GDI and TGDI engines are uniquely susceptible to a low-speed pre-ignition (LSPI) phenomenon which, if unaddressed, can cause catastrophic engine failure. Importantly, the lubricant can dramatically curb or exacerbate LSPI in TGDI engines such that lubricant performance is more important than ever and must protect and preserve a wider range of engine hardware in the vehicle carpark.

As part of automaker efforts to extract greater efficiency from their engine hardware—whether it be port fuel or direct injected—accessing lower viscosity lubricants is widely recognised as a key approach to reduce engine friction and drive up fuel efficiency. This discovery has been reflected in the ILSAC specification which, for the first time, has been split into two sub categories: GF-6A and GF-6B. The latter covers lower viscosity XW-16 (X= 0, 5). GF-6A certified lubricants are suitable for use in all vehicles, whereas GF-6B lubricants are only suitable for use in new-model vehicles that require lower viscosity.

The ILSAC specification evolution to include broader viscosity coverage is representative of other global industry and OEM specifications wherein there is a drive towards lower viscosity which creates unique formulating challenges. For example, incorporation of macromolecular additives (e.g. detergents and dispersants) becomes increasingly challenging in lighter viscosity grades because these components themselves impart unhelpful viscosity to the lubricant formulation.

This challenge is further exacerbated since automakers expect the same level of cleanliness and durability from the lubricant in hardware designed for low viscosity as mandated in traditional hardware that uses higher viscosity grades. Thus lubricant designers must still formulate with high levels of these macromolecules in low viscosity grades—and, in some cases, new designer detergents and dispersants (with higher efficacy and low viscometric impact) are now required to serve the low viscosity formulation box. In addition, the role of performance polymers and base oil selection becomes even more critical. To summarise, new additive technology is required to deliver efficiency without compromising durability over a wider range of performance parameters, operating conditions and viscosity grades. Next generation lubricants are quite different than their previous counterparts and point to a future where product lines will become increasingly complex to meet the evolving requirements of new engine technology.

In Europe, where diesel fuel is used in conjunction with gasoline in passenger car vehicle applications, a different shift has taken place. Hardline emissions legislation has required the widespread implementation of emissions aftertreatment devices in vehicles. Aftertreatment devices have their own unique requirements for lubricant performance and have spurred the necessity of formulations that have reduced sulfated ash, phosphorous, sulfur (SAPS) content. As such, the European Automobile Manufacturers’ Association (ACEA), along with several European OEMs, has established low-SAPS as a necessary performance attribute of modern lubricants.

ILSAC GF-6B and low-SAPs ACEA-compliant formulations are two lubricant categories that characterise the latest in state-of-the-art passenger car lubricant technology. Their adoption and widespread use will be important developments in the near-term future of the industry.

An evolution of branding

As the necessary performance of passenger car lubricants continues to rise higher, the traditional ways that lubricant manufacturers have marketed their products is changing as well. For example, many available passenger car lubricants that are of the same viscosity grade are typically formulated with the same high-quality base oils. Today, an SAE 20W-50 lubricant essentially provides the same levels of engine protection and durability as a 10W-40 or a 5W-30. The same can be said of semi-synthetic versus full synthetic formulations—both provide desirable performance. This means that the conventional ‘good, better, best’ positioning is becoming less relevant in the modern marketplace.

Simultaneously, many passenger car OEMs have begun to specify certain levels of performance for lubricants that are recommended for use in their vehicles, in addition to industry standards like those set by ILSAC or ACEA. All of this contributes to an increasingly complex environment when it comes to appropriate application of lubricants in modern vehicles. Into the future, it will be the shared responsibility of OEMs and the lubricants industry to help educate consumers in making the right selections.

Never before has the passenger car lubricant market been as dynamic and sophisticated as it is today—and it only stands to become more so tomorrow

Formulation challenges

Finally, greater attention and stricter regulations are being levied at many different chemistries that the lubricants industry has long used to make and formulate quality products. The European Union’s REACH regulation has driven much of this, adopted to help the world move cleaner, improving the protection of human health and the environment from risks that can be posed by certain chemicals. As a result, existing additive technology may need to be reformulated.

These chemical regulations limit the scope of available new chemistries, and the periodic table continues to shrink of accessible elements for synthetic chemists, which means creating more from less. Additionally, optimal resource-intensive processes are new critical design criteria for any new additive technologies. It will be necessary to create additional design criteria beyond lubrication performance (e.g., viscosity profile). Dispersants, detergents, antioxidant systems and anticorrosion/friction reduction systems, along with performance polymers, will all be affected. As a result, formulators will need to learn how to create efficient, safe and sustainable chemistries and products for consumers.

Collaboration for a complex road ahead

Never before has the passenger car lubricant market been as dynamic and sophisticated as it is today—and it only stands to become more so tomorrow. There are many influencing factors to consider across the value chain, with increasingly diverse requirements for lubricant technology.

Many industry players believe it is essential to design the lubricant for the right application, and it is the industry’s collective responsibility to ensure that the right lubricant is used throughout a vehicle’s lifetime. Closer engagement and partnership between automakers, lubricant formulators, and additive suppliers will be essential for shared success in the years to come.

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About the authors: Dr. Colin Morton is Senior Director for Consumer Engine Lubricants at The Lubrizol Corporation. Dr. Ewan Delbridge is Director of Technology for Consumer Engine Lubricants at The Lubrizol Corporation