Advanced lubricant and fuel additives are key to helping vehicles meet emissions targets, writes Brett Blackburn
In nearly every major automotive market on earth, modern regulatory measures and government initiatives are spurring OEMs to deliver vehicles that produce lower levels of emissions and higher levels of fuel efficiency than ever before. It’s become the era of efficiency, and there’s no indication it will be short-lived. OEMs continue to introduce a range of new hardware advancements to meet emissions targets, but they won’t get the job done on their own. Critically, high-performance lubricants and fuels will be required to help new hardware meet its full potential. And those lubricants and fuels have their own contributions to make toward overall efficiency gains.
For these reasons, it’s incumbent upon the entire value chain to develop, distribute and utilise these high-performance fluids across applications. The era of efficiency depends on it.
Making an impact on modern drivetrains
One of the most commonplace and effective methods to immediately mitigate the impact of emissions from modern drivetrains is to incorporate an aftertreatment device. OEMs are doing this throughout the industry. In the passenger car space, gasoline particulate filters (GPFs) have been increasingly implemented, particularly in Europe as emissions standards grow stricter. First introduced into mass production in 2014, GPFs have since become increasingly common in a wide variety of makes and models.
The majority of GPF technology routes engine exhaust gases through a porous ceramic filter. Once inside the filter, the particles in the exhaust are captured in the fine pores of the channel walls. A small fraction of the engine lubricant is burned in the combustion process, which also flows into the filter. As it does so it creates an ash layer on the channel walls. Initially, lubricant ash reduces pore size and in fact improves filtration efficiency—but only a small amount is required to accomplish this improvement. Once larger amounts build up, they can produce long-term blockage, which impacts GPF power and efficiency. In addition, ash composition also affects blockage, as its structure may be porous or nonporous. Low Sulfated Ash, Phosphorous, Sulfur (Low SAPS) lubricants are therefore essential to long-term emissions compliance. Suboptimal lubricant performance can lead to device failure and warranty claims.
In the diesel space, several other technologies have been applied across the globe, including diesel particulate filters (DPFs), diesel oxidation catalysts (DOCs) and selective catalytic reduction (SCR). These devices have been shown to trap and oxidise up to 100% of carbon soot particulates in the engine exhaust and as such, have proven effective at meeting the evolving emissions targets in recent years.
Like GPFs, DPFs can become blocked with ash, and rendered ineffective far more quickly without Low SAPS formulations. Choosing an engine oil with low SAPS will reduce DPF blockage, ensuring cleaner exhaust gas, vehicle efficiency, and less maintenance. Further, deposit control additives can help reduce soot loading, therefore helping to reduce the likelihood of DPF blockage. Suboptimal performance can lead to the need for more frequent regens—creating extra downtime and wasting excess fuel.
Lower viscosity, higher efficiency
Beyond their ability to better enable technology like GPFs and DPFs, lubricants can, in and of themselves, lead to fuel economy benefits. Lower-viscosity formulations across the passenger car and heavy-duty spectrum can help engines operate more efficiently and achieve fuel economy gains. They do this by reducing friction between moving engine parts, allowing those parts to move with less resistance and more relative power. But this doesn’t happen by simply formulating thinner fluids; lower-viscosity formulations require the right additive chemistry to deliver reliable protection and performance.
It’s likely that OEMs will continue to specify lower and lower viscosity fluids for use in their vehicles, especially in the passenger car market. Advanced additive chemistry has helped grant OEMs the confidence that such fluids will provide robust protection in the field for the lifetime of the vehicles.
Enhancing widespread fuel quality with additives
In both the passenger car and heavy-duty diesel segments, fuel quality has a significant impact on new engine hardware’s ability to run cleanly and efficiently. For example, in the passenger car segment, OEMs are increasingly utilising gasoline direct injection (GDI) technology to achieve fuel economy gains. However, these engines have a higher propensity for deposit buildup, which can be detrimental to engine operation and fuel economy. GDI engines are designed to extremely tight tolerances and intended to run optimally in clean environments, and in part rely on higher-quality fuels to contribute to enhanced engine cleanliness. Gasoline that incorporates the right additive technology can help eliminate this carbon buildup, enabling GDI engines to operate at peak efficiency throughout their lives.
Suboptimal lubricant performance can lead to device failure and warranty claims
In diesel applications, optimally additised diesel fuel can have an even bigger impact. Engine cleanliness is important for efficiency here, too, and deposit control additives also help keep fuel injectors, DPFs and other components free of buildup and soot. This is crucial for driver uptime, as cleaner DPFs can reduce the need for time- and fuel-consuming regens (the process in which diesel engines run hotter to burn off accumulated soot from the DPF). Though regen is an inevitability for fleets and their active maintenance of DPFs, cleaner fuels that are treated with the right deposit control additives can help reduce the frequency of regens or other forms of time-consuming maintenance, helping fleets save time and money over the long term.
Another important factor to consider in the heavy-duty space is the increasing relevance of renewable diesel fuel. More formally called hydrogenation-derived renewable diesel (HDRD), renewable diesel is chemically the same as petroleum diesel and may be used in its pure form—called R100—as a drop-in replacement for ULSD. This makes it a highly convenient and effective means to reduce carbon intensity on a potentially broad scale.
But if renewable diesel is untreated, the benefits come with their tradeoffs. One of the most significant is renewable diesel’s inherent lubricity—e.g., the fuel’s ability to help prevent wear in metal-on-metal applications as it travels through the combustion system. This is particularly important within a diesel engine’s fuel injection system, where fuel travels through high-pressure pumps designed to tight tolerances (much like modern GDI engines). A good fuel—be it renewable or otherwise—requires certain lubricating properties that can help prevent premature wear, and the right additives.
Looking ahead, the right lubricants and fuels will be essential as the automotive industry as a whole moves toward a more fuel-efficient future. High-performance additive chemistry will be increasingly essential in fuels and lubricants. Strong partnerships across the value chain—between fuel and lubricant marketers, additive suppliers, and OEMs—can help make it happen.
About the author: Brett Blackburn is Fuels Product Manager at Lubrizol