Oil is changing rapidly to keep abreast of modern engine technology and that ultimate proving ground, formula one, plays a big part...
While Lewis Hamilton answers questions about the 2018 Formula One season, his team-mate Valtteri Bottas climbs into the Mercedes-AMG W07 racecar. The countdown begins and, as the lights go out, he revs the engine to a cheering crowd.
No, this isn’t the start of a race but the opening of the new Petronas research and development facility in Turin, Italy. The Malaysian energy giant, you may know, is a majority stakeholder in the South African fuel company, Engen. Since the firm partnered with the Mercedes-AMG F1 team six years ago, it has created 100 new oil and 200 new fuel formulations. That is rapid progress considering it takes 5 000 litres of oil and 30 000 km equivalent testing on an engine dyno to validate a new oil specification.
The challenge facing oil companies today is to both produce oils for modern, downsized turbo engines that reduce friction to lower fuel consumption and CO2 emissions, and lengthen service intervals, while still providing adequate lubrication to ensure the long-term durability of the unit. We spoke to a few of the Petronas experts on hand to get an idea of the development process.
1. An engine oil is born
Crude oil is still the major source of hydrocarbons used to create base oils during a refinery process. These base oils are then mixed with additives to produce experimental engine oils. Think of it as a very complex recipe where the ingredients play a crucial role in the final properties of the oil.
2. In the lab
The next step is laboratory testing and validation, where some of the main testing includes:
i. Stability and oxidation performance impacts on the shelf life, as well as service life, during operational temperatures in an internal-combustion engine.
ii. Viscosity testing is done at cold temperatures of -40 °C and at 100 °C, as per standard test protocols defined, by example, ASTM D445 (standard test method for kinematic viscosity).
iii. A spectrometer is used to analyse the exact chemical content of an oil sample. This can be utilised during the development of oil, or to test used-oil samples for impurities. It is also a clever method of looking at competitor products to learn their secrets. At all the F1 races, Petronas has a mobile test lab which analyses oil samples and determines if any foreign metal molecules are present that may point to wear in the engine. This is similar to a human blood test showing possible illness. It can, for example, predict a bearing failure and prevent one long before it happens during a race.
iv. Tribology testing is the study of friction, wear and lubrication on surfaces in relative motion. Popular methods of testing include rotating-disc-and-ball testing, as well as a high-frequency, oscillating sliding test to measure wear rates.
3. On the engine dyno
The oil’s final validation test takes place on a test bench in the engine for which it was designed. This type of testing is extremely expensive because thousands of kilometres must be simulated on the dyno, running various drive cycles and load cases.
F1 test cells can accurately simulate the running of every circuit on the tour and engineers can experiment with optimal ways of utilising the energy in the fuel and kinetic energy recovered to produce the fastest lap time. They take regular oil samples for spectrometer analysis but other techniques such as radiographic testing which involves radioactive elements in the metal structures, are also used to identify and monitor wear, even in real time.
Race to road
Petronas has not only been involved with the Mercedes-AMG team as a sponsor, but also as a technical partner to accelerate the development of lubricants and fuels. According to global technology manager, Dr Andrea Dolfi, because performance is paramount, the requirements of oil in an F1 engine are vastly different to engines in production vehicles. In a race car, the oil has to last just 300 km (although the engine’s durability is more important than ever with only three powertrains allowed for the 2018 season). Furthermore, the oil in an F1 car does not need to be multigrade as the engine does not experience winter conditions during racing and product costs is not an issue.
There are, however, learnings from F1 that can be carried over to the oil products for road cars. Cooling performance is one such example, as the average oil temperature in an F1 engine is not that much higher than an engine in a production vehicle that is driven hard. Because of the high in-cylinder pressures and specific power output of the 1,6-litre turbocharged V6 units which deliver more than 500 kW, the main difference is the high peak temperatures at the boundary layers in the combustion chamber.
Lubricants can carry this heat away and enhance engine durability (all modern turbo engines have oil jets underneath the pistons to help cool the crowns). This has given rise to CoolTech technology now also found in Petronas’ Synthium products. Another example is ultra-low viscosity oils and Petronas has just launched an ultra-low 0W-16 engine oil.
The future for oil companies
Oil companies such as Petronas are naturally aware of the shift towards electric vehicles and the impact this may have on their long-term sustainability. The number of all-electric vehicles in the global market (including second-hand cars) is still tiny but it is growing rapidly. That said, hybrid-vehicle sales are accelerating, too, and they employ internal-combustion tech that still needs oil (and fuel). Therefore, according to predictions, from an oil dependency perspective, the market will remain stable up to 2040. In the meantime, Petronas is developing a variety of products, including cooling fluids used in battery packs (like the Mercedes-AMG Formula One car), to ensure it evolves, too.
Durability vs. speed: A driver’s perspective
There is always a trade-off between having a car that is fast, and one which is durable, a balance the lubrication industry works hard to nail. A lower-viscosity oil may reduce engine friction and therefore increases power output, but engine durability can also be compromised. More than ever before, a driver needs to be more sensitive to protecting the powertrain while trying to win a race.
I had the opportunity to pose a few questions to four-time world champion Lewis Hamilton and his team-mate, Valtteri Bottas.
CAR: Lewis, is it true that a modern-day race driver needs to be more of an engineer than in the past? And what can you do to protect the engine if the telemetry tells the team there may be a problem with the powertrain?
LH: Yes, that is true. I have a button on the steering wheel to push that records a marker in the telemetry data for the engineers to analyse if I notice a stumble or other problem. The engineers on the pit wall can instruct me to turn down the power and alter my shift points to protect the engine. In case of a sensor fault, I can disable the sensor by feeding the sensor number to the control unit, which is sometimes difficult in the heat of battle.
CAR: Surely racing drivers want to go as fast as possible all the time? Would you risk powertrain failure when an opportunity to overtake to win the race presents itself?
VB: You tend to save the engine during certain parts of the race, but when an opportunity presents itself, I would always demand maximum performance from the powertrain and worry about the consequences later...
Author: Nicol Louw