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Engine oil viscosity in Formula 1

In recent years, the FIA has introduced "engine freeze" regulations which prohibit significant engine developments in Formula 1. However, these rules do not apply to the engine oils used. Increasing power in F1 engines can serve as an advantage in races. Read this article to find out how engine oil viscosity contributes to increasing power in Formula 1 engines.

Formula 1

Formula 1 cars can race at speeds of up to approximately 380 km/h (240 mph) with engines currently limited in performance to a maximum of 15000 RPM. Therefore, they are the fastest road racing cars in the world. The cars are capable of lateral acceleration in excess of five g in corners. The formula has evolved through the history of the sport, also having a significant effect on job creation and a major merchandising environment. However, the major fascination throughout the decades has been the cars and their powerful engines. The performance of the cars is dependent on many factors, uniting cutting-edge research, innovation, talent, perseverance, testing, and courage.

Engine oil lubrication

Formula 1 car during a race

Figure 1: Formula 1 car during a race

The engine lubrication, and especially the synthetic engine oils used in F1, remains one of the few areas that is not highly regulated. This is why engine oils producers spend a lot of time and money developing oils specifically for the high-performance F1 engines.

The primary function of the lubricant in Formula 1 engines – as in any other internal combustion engine – is to form a film between the moving parts to prevent any metal-to-metal contact. Any direct contact between moving parts can lead, at the worst, to a breakdown due to seizing or, at best, accelerated wear of the engine. This must be avoided as the number of engines that may be used per season is limited. Good oil must protect engine components at temperatures of up to 300 °C without having too low viscosity, which would lead to insufficient protection against wear, evaporating, or carbonizing.

Difference between the Formula 1 engine oils and regular engines oils

In a Formula 1 engine, which develops a power output that is six to ten times higher than that of the motor of a regular car, the mechanical stress increases exponentially. Developing the maximum power of 750 HP to 900 HP (560 kW to 670 kW) at 15000 RPM, the piston speed in the cylinder over a short distance is huge, equating to an incredible acceleration of nearly 9000 times gravity. The enormous mechanical stress on the connecting rod bearings is a result of the massive accelerations and decelerations, so the lubricating film must protect the parts against huge forces. In addition to friction, there are other processes that use up energy and therefore power, and this is what the engineers attempt to reduce.

In considering how the lubricant contributes to increasing power, the fundamental aspect is the engine oil viscosity. Through specific research on lubricants’ viscosity and friction at all parts of the engine and gearbox, the lubricants developed by Formula 1 suppliers make it possible to gain several percent in power. In a competitive situation in which any gain in power can ensure a decisive strategic advantage, this contribution can be decisive. 

Determination of engine oil viscosity

The measurements need to be highly precise for the thorough and innovative research and development. However, having in mind what is at stake in Formula 1 and keeping in mind the different ambient conditions at all the races, the engine oils are often tested at the racing site. Ideally, the same instrument is used in the factory and at the race track; it should be rather small and insensitive to vibrations so that it can be used in a mobile lab truck. It should work out-of-the box, without long set-up times or tedious calibrations. The measurement should be fast and reliable, as a deviation of only 1 % viscosity  can equal several horsepower!

The highly precise SVM Viscometers fulfill these criteria. They combine a friction-free rotational viscometer with a U-tube digital density meter in the same Peltier thermostat block:

set-up of SVM Viscometer

Figure 2 SVM Viscometer viscosity measuring principle

SVM Viscometer series

The highly precise viscometers of the SVM series are based on a rotational measuring principle and have an integrated density measuring cell. The small viscosity measuring cell contains a tube which rotates at a constant speed and is filled with sample fluid. A measuring rotor with a built-in magnet floats freely in the sample. The sample’s shear forces drive the rotor while magnetic effects retard its rotation. Shortly after the measurement starts, the rotor reaches equilibrium speed. This speed is a measure of the fluid‘s viscosity (Figure 1).

This means a single measuring cycle on a sample volume as low as 2.5 mL yields the kinematic viscosity, density, dynamic viscosity, Viscosity Index, API grades, and more – within minutes. Built-in extrapolations allow for calculations of viscosity and density for any temperature.