Stand in a traffic jam on a major highway on a hot July afternoon. Do you notice the faint bluish haze hanging above the stream of vehicles? We are accustomed to blaming fuel for it. Yet even in Europe, where the quality of gasoline and diesel is strictly regulated and older vehicles are gradually being removed from city centers, smog remains a persistent problem. There is another source of pollution that is rarely discussed, despite its significant contribution to urban air pollution: engine oil.

Here is a simple but important fact: if your vehicle consumes one liter of engine oil every 10,000 kilometers (a rate that many automakers still consider acceptable), that liter does not simply disappear. It is either burned in the combustion chamber and released through the exhaust as ash, oxides, and fine particulate matter, or it evaporates, releasing hydrocarbons into the atmosphere. Across a major metropolitan area with millions of vehicles, this translates into hundreds of tons of lubricant entering the environment every year.

While the world continues to debate when electric vehicles will finally replace internal combustion engines, we still need clean air today. Chemical engineers already have a solution that can make an immediate difference: the transition to biosynthetic lubricants. This is not about saving polar bears in the Arctic—it is about improving the quality of the air outside your own window. Let’s take a closer look at how plant-derived lubricants are transforming the urban environment at the molecular level.

Contents

Expert Opinion
Carbon Footprint: Looking Beyond the Tailpipe
NOACK Volatility and Urban Smog: Why Engine Oil Evaporates
The Enemies of Emission Control Systems: Sulfur, Phosphorus, and Ash
Friction and Global Warming
Biodegradability: Not Just for Forests, but for Cities Too
Conclusion

Juri Sudheimer: Biosynthetic Lubricants Are Not a Trend—They Are an Engineering Solution

To better understand the technological aspects of biosynthetic lubricants, we spoke with Juri Sudheimer, Founder founder of the MANNOL brand, a company specializing in the development and manufacture of lubricants for global markets. His responsibilities include introducing new technologies and expanding the company’s product portfolio, including biosynthetic lubricant solutions.

“When we talk about bio-based oils, we are not talking about returning to something primitive. We are talking about more controlled chemistry. Engineered molecules allow us to control properties such as volatility, stability, and metal interaction at a level that conventional petroleum-based products simply cannot achieve,” he explains.

According to Juri Sudheimer, this is precisely why biosynthetic lubricants are increasingly being viewed as a practical solution capable of addressing several challenges simultaneously—from reducing emissions to extending engine life.

Carbon Footprint: Looking Beyond the Tailpipe

Environmental science uses the concept of Life Cycle Assessment (LCA) to evaluate the total environmental impact of a product from “cradle to grave.” Applying this methodology to conventional engine oils and biosynthetic lubricants reveals a striking difference.

Traditional engine oils—whether mineral, hydrocracked (Group III), or PAO-based (Group IV)—begin with crude oil extraction. Drilling, transportation by tanker, and the energy-intensive refining and hydrocracking processes all generate substantial CO₂ emissions long before the finished lubricant reaches the consumer.

The production of biosynthetic lubricants, particularly esters and estolides, follows a fundamentally different pathway. Their raw materials originate from renewable biological sources such as rapeseed, soybeans, castor beans, or microalgae. During growth, these feedstocks perform the process they have perfected over millions of years: photosynthesis. They absorb carbon dioxide directly from the atmosphere.

According to the USDA BioPreferred® Program, the production of certain bio-based lubricant base oils can achieve a negative carbon footprint, meaning that more greenhouse gases are removed from the atmosphere during production than are emitted throughout the manufacturing process. Biosynthetic Technologies, a pioneer in estolide chemistry, has published research demonstrating that its bio-based oils reduce greenhouse gas emissions by 60–80% compared with conventional Group III hydrocracked and Group IV PAO base oils. Within the chemical industry, this represents far more than an incremental improvement—it reflects a fundamental technological shift.

Skeptics often raise a legitimate concern: could increased demand for bio-based lubricants create a “food versus fuel” conflict? Would using soybean oil in engines drive up food prices?

The answer lies in second-generation feedstocks. Modern industrial biotechnology is moving away from food crops and increasingly utilizing agricultural by-products, industrial waste streams, and, most promisingly, aquatic biomass. Microalgae can be cultivated in saltwater within enclosed bioreactors located on land unsuitable for agriculture. They do not compete with food production for arable land, while delivering oil yields per hectare that are many times greater than those of conventional oilseed crops.

NOACK Volatility and Urban Smog: Why Engine Oil Evaporates

Let’s return to that faint bluish haze above the highway. One of the most important performance characteristics of any engine oil is NOACK volatility, a standardized test measuring the percentage of oil that evaporates after one hour at 250°C.

Modern engines expose lubricants to extremely high temperatures, particularly around the piston rings and turbocharger bearings. Petroleum-based oils—especially today’s low-viscosity grades such as 0W-20 and 0W-16, widely used to improve fuel economy—are more susceptible to evaporation. The reason lies in the inherently heterogeneous molecular composition of crude oil. Even after extensive refining, lighter hydrocarbon fractions remain within the base oil. These shorter molecular chains are the first to evaporate under heat.

As these light fractions vaporize, they form an oil mist that passes through the crankcase ventilation system into the intake manifold and ultimately the combustion chamber. There, incomplete combustion of these vapors generates fine particulate matter that is released into the atmosphere and eventually inhaled by people living in urban environments.

Biosynthetic base oils, including esters and estolides, possess both high molecular polarity and exceptional structural uniformity. Their molecules are synthesized with precisely controlled chain lengths and molecular weights, eliminating the light fractions responsible for excessive evaporation. In addition, their polar molecular structure creates stronger intermolecular attraction than the non-polar hydrocarbons found in petroleum oils. As a result, biosynthetic lubricants exhibit significantly lower volatility and substantially higher flash points.

From a physical standpoint, two lubricants with the same viscosity can perform very differently. A high-quality ester-based lubricant typically evaporates far less than a conventional petroleum-derived product. Less evaporation means fewer hydrocarbons and fewer oil-derived aerosols entering the atmosphere—resulting in a measurable reduction in urban air pollution.

Juri Sudheimer: Oil Volatility Is a Direct Contributor to Urban Smog

According to Juri Sudheimer, lubricant volatility is one of the most overlooked contributors to air pollution in modern cities.

“NOACK is not just a laboratory figure. It directly reflects how much engine oil ultimately ends up in the atmosphere. The higher the volatility, the more hydrocarbons and particulate matter are released through the exhaust and into the air,” he explains.

He notes that this is precisely where biosynthetic base oils offer one of their greatest advantages: a carefully engineered molecular structure free of the lighter fractions that evaporate first under high operating temperatures.

The Enemies of Emission Control Systems: Sulfur, Phosphorus, and Ash

Today’s automobile is, in many respects, a sophisticated chemical processing system on wheels. To comply with Euro 5 and Euro 6 emission standards, modern vehicles are equipped with highly advanced exhaust aftertreatment technologies, including Three-Way Catalysts (TWC) and particulate filters such as Diesel Particulate Filters (DPF) and Gasoline Particulate Filters (GPF).

The primary enemies of these systems are collectively known as SAPS—Sulfated Ash, Phosphorus, and Sulfur.

Sulfur poisons the catalyst’s active surface, reducing its ability to convert nitrogen oxides (NOₓ) into harmless compounds.

Ash—the non-combustible residue originating from lubricant additives and burned engine oil—gradually clogs the porous structure of particulate filters, significantly reducing their efficiency. While ash has less impact on three-way catalysts than on particulate filters, it still contributes to long-term degradation of emission control performance.

Because crude oil is a naturally occurring fossil resource, completely eliminating sulfur impurities is both technically difficult and economically expensive. Even premium hydrocracked base oils may contain trace amounts of sulfur. Biosynthetic base oils, by contrast, are inherently cleaner. Plant-derived feedstocks contain neither sulfur nor the aromatic hydrocarbons naturally present in crude oil.

There is another important advantage recognized by lubrication engineers. Conventional engine oils require substantial concentrations of anti-wear additives, the best known being ZDDP (zinc dialkyldithiophosphate). Although ZDDP provides outstanding wear protection, it also introduces significant amounts of phosphorus and sulfur—both of which shorten catalyst life.

Biosynthetic esters possess natural lubricity due to their polar molecular structure. Their inherent tribological properties reduce friction and wear without relying as heavily on conventional additive chemistry. This enables lubricant formulators to significantly reduce ZDDP concentrations while maintaining excellent engine protection.

As a result, manufacturers can formulate Low SAPS engine oils far more effectively using biosynthetic base stocks.

What does this mean in practice?

Catalytic converters remain effective for much longer. A vehicle that has accumulated 200,000 kilometers using biosynthetic lubricants is far more likely to maintain emission-control performance comparable to that of a new vehicle. With conventional lubricants, emission control systems often deteriorate by this mileage, leaving owners facing expensive catalyst replacement after a persistent Check Engine warning.

By extending the service life of emission control systems, biosynthetic lubricants help maintain cleaner air not only during laboratory certification testing but throughout a vehicle’s real-world operating life.

Juri Sudheimer: Biosynthetic Lubricants Represent the Next Stage in Engine Oil Evolution

Technological advantages alone are not enough; it is equally important to understand how these innovations translate into real-world applications and market adoption. To gain this perspective, we spoke with Juri Sudheimer, who has been involved in lubricant development for more than three decades.

“The engine oil industry has always evolved through compromises—balancing engine protection, fuel economy, and environmental performance. Biosynthetic base oils allow us to rethink that compromise. We achieve cleaner combustion, reduce the load on emission control systems, and at the same time preserve engine durability,” says Juri Sudheimer.

Friction and Global Warming

One of the best-known tribological properties of biosynthetic lubricants is the ability of their polar molecules to form an exceptionally strong protective film on metal surfaces. But what does this have to do with the environment?

The connection is direct.

The coefficient of friction inside an engine has a measurable impact on overall efficiency. The less energy required to rotate shafts, move pistons, and operate the oil pump, the less fuel must be burned to travel the same distance.

In addition, biosynthetic lubricants—particularly estolides—possess an inherently high viscosity index. Conventional petroleum oils naturally become much thinner as temperatures rise. To maintain adequate oil film strength under high operating temperatures, formulators must add viscosity index improvers—long polymer chains designed to resist thinning.

The problem is that under severe mechanical loads these polymers gradually break down through mechanical shear, causing viscosity loss, increased friction, and higher fuel consumption.

Biosynthetic lubricants require significantly fewer viscosity modifiers because their viscosity characteristics are naturally stable. As a result, engines operate closer to their intended design parameters throughout the oil’s service life.

Studies, including testing conducted under the CEC L-54-96 (M111) European fuel economy procedure, demonstrate that high-performance friction modifiers based on esters and estolides can reduce fuel consumption. The improvement—typically 1.5–3%—may appear modest at first glance, but its cumulative impact is substantial.

Berlin alone has approximately 1.2 million registered vehicles. If each consumed just 2% less fuel, millions of liters of gasoline would remain unburned every year, preventing thousands of tons of CO₂ from entering the atmosphere.

Improving engine efficiency by fractions of a percent is not simply a marketing exercise—it is one of the most practical ways to reduce humanity’s environmental impact while internal combustion engines remain an essential part of global transportation.

Biodegradability: Not Just for Forests, but for Cities Too

Biodegradability is often associated exclusively with forestry equipment, where hydraulic hose failures must not contaminate soil and surrounding ecosystems. Yet cities are ecosystems as well—only built from concrete rather than trees.

Look at the asphalt in parking lots or at busy intersections. The dark stains are engine oil. Rain washes these residues into stormwater drainage systems, from which—realistically—they often reach urban rivers and lakes with only minimal treatment. Petroleum films on the water surface reduce oxygen transfer, threatening fish and aquatic microorganisms.

Here, biosynthetic lubricants offer an undeniable advantage.

Lubricants formulated with esters and estolides are classified as Readily Biodegradable. According to the OECD 301B biodegradability test, microorganisms decompose at least 60% of such products within 28 days, converting them into simple natural compounds.

By comparison, synthetic PAO (polyalphaolefin) lubricants typically biodegrade by only 5–10% over the same period, allowing them to persist in soil and water for years.

In both Europe and the United States, this is no longer merely an environmental recommendation—it has become regulatory policy.

For example, the United States Vessel General Permit (VGP) requires vessels operating in U.S. waters to use Environmentally Acceptable Lubricants (EALs) in all equipment with potential water contact.

Similarly, the EU Ecolabel for lubricants requires high biodegradability and low aquatic toxicity.

Using biosynthetic lubricants in municipal equipment—street sweepers, water trucks, buses, and other public service vehicles—is therefore not simply an environmental preference. It is an essential component of responsible urban infrastructure. Oil leaks may be unavoidable, but their environmental consequences do not have to be.

Conclusion

Biosynthetic lubricants are often dismissed as expensive products for enthusiasts or as a concession to environmental politics. In reality, they represent a practical engineering solution to the technological limitations of petroleum-based lubrication.

The industry has largely reached the practical limits of refining crude oil. Achieving cleaner air in modern cities requires changing the chemistry of lubrication itself.

Lubricants derived from renewable plant sources and microalgae provide a comprehensive solution.

They reduce the carbon footprint from the very beginning of the production process.

They exhibit lower volatility, helping reduce smog-forming emissions.

They contain no sulfur and allow phosphorus levels to be significantly reduced, extending the service life of automotive catalytic converters.

They are readily biodegradable, making accidental leaks substantially less harmful to the environment.

This is not a futuristic concept. Estolides and synthetic esters are already being used in modern engines, and their adoption is expected to accelerate significantly with the introduction of Euro 7 emissions standards.

In the near future, the question at the service counter—“Would you prefer conventional synthetic or bio-based oil?”—may become just as routine as choosing between regular and premium gasoline.

And to appreciate the significance of that choice, all you will need to do is step outside the workshop, walk onto a city street, and take a deep breath of cleaner air.