What are the factors that will most influence the design and manufacture of tomorrow’s cars? It doesn’t take a crystal ball to predict that drivers in the middle of the 21st century will likely be behind the wheels of cleaner, faster and cheaper vehicles. Certainly, the automobile industry is already well on the road to pursuing many of these goals, often driven by government legislation and consumer demands.
Today’s technology has allowed car manufacturers to produce smaller, yet more powerful and efficient engines. Their aim is to deliver increased fuel economy, reduced emissions and high performance. But the focus on down-sizing, turbo-charging and advanced designs have meant engine pressures have almost doubled over the last 30 years.
With the highest pressures found in the camshaft – the area of the engine where parts called lobes meet the valves and push them open – these parts need protection when they come into contact. That comes from a very thin layer of oil.
Today’s engine oils operate under higher temperatures and greater stress than ever before. To address these challenges, BP’s chemists and engineers in its lubricants business have generated a new molecule to provide extra strength in the oil films of its Castrol EDGE product range.
This technology journey began several years ago in a laboratory in New Jersey, US. “We’re always looking at different chemistries or components that may allow us to enhance performance attributes of our lubricants,” says Mario Esposito, Castrol’s team leader for polymer development and passenger car oils, at the Wayne Technology Center.
“Our research initiatives are essential,” he adds. “We formulate our lubricants around individual, proprietary ingredients, creating a ‘hand crafted’ differentiated offer, and with Castrol EDGE, we aimed to develop a performance additive that made the lubricant stronger.”
Through their analysis, the chemists pinpointed a titanium molecule that displayed the sought-after characteristics: the additive changes the freezing pressure of the lubricant under extreme pressure and it actively thickens and reinforces the oil film. In an engine, that means it offers greater protection at high-pressure contact points, giving the oil the ability to keep metal surfaces apart more effectively with a cushioning effect.
The laboratory results needed rigorous testing in the real world to make sure that the claims could be substantiated. Castrol’s team in Pangbourne, UK, led this phase of development to formulate the oil and test the effects of titanium to reduce friction and resist film breakdown.
“The next stage involved blending the new formulation with our laboratory technicians to optimize the viscosity of the product and later run the prototype formulations through engine tests,” says Simon Gurney, automotive engineer and senior development technologist. “We test parameters such as impact on engine wear, sludge build-up and piston cleanliness. Some tests can take several weeks to run – the longest was a 900-hour engine test. These are extreme by nature, creating conditions that will never be seen in a car on the road.”
Tests also followed with original equipment manufacturers (OEMs) and other research facilities. “We worked with a Scottish university to independently test the additive under very high pressure,” says senior technologist, Gareth Dowd. “This confirmed that adding the titanium improved fluid strength by changing its physical behaviour.”
Castrol’s team of chemists built that molecule from scratch, as polymer research manager, Richard Sauer explains: “We were assessing a range of transition elements, trying to identify which one would bring value to a finished oil. We needed to assess the advantages of each element, looking at factors such as engine deposits and wear control.
“We looked at how a metal may be incorporated onto a polymer to complete a finished engine oil with the desired performance attributes. Generally speaking, functional polymers bring extra performance characteristics to a completed formula. As well as identifying the chemistry, we also had to work on putting together a viable commercial process.”
When the titanium-containing molecule comes under pressure in the engine, it momentarily causes the oil to form a semi-solid, almost like cushioning pads between the points of contact.
The oil stiffens under pressure and the titanium enhances this – when the pressure is relieved, the oil converts back to its usual liquid state and flows around the engine.
Results confirmed that Titanium FST™ (fluid strength technology) doubles the film strength of Castrol EDGE, preventing oil film breakdown and reducing friction. The culmination of more than seven years’ efforts by Castrol experts came earlier this year when the product was launched in Europe and the Middle East, joining the US and Asia markets where it had already been on sale.
“This is now a global product with a global ingredient,” says Tony Smith, Castrol senior adviser for claims and demonstrations. “The titanium additive contributes to a stronger lubricant for today’s engines that are shrinking in size but producing more and more power.
“To synthesize a molecule and make it a commercial reality takes a huge global effort over many years – colleagues from manufacturing to supply chain, marketing to chemical inventory registration are all involved.”
But the work does not stop there. Even when a Castrol product is on the shelves, technologists still need to keep a watchful eye on ever-changing legislation that prompts alterations to industry specifications and evolving vehicle designs by OEMs. It’s a pretty safe bet that manufacturers will continue to demand the highest quality consumable fluids to help engines run cleanly and reduce emissions in the years to come.
“At Castrol, we know the importance of looking at trends, and not only responding to industry requirements – but going beyond them,” concludes Smith. “Challenges for the future will likely include lower viscosity oils and changes in fuel types, such as biofuels. We’re working to be ready in advance of all these needs, with more new and unique Castrol technologies.”