Club Motul: Why MOTUL 20w50?

Oil is often dubbed the lifeblood of the engine as it wouldn’t last even a mile without it. That’s why it is so important to use a high-quality oil that is suited to the needs of your engine.

MOTUL 20w50 has been formulated specifically for engines originally produced between the years of 1950 and 1970. The casting and metallurgy processes of the time require different lubrication needs compared to later vehicles.

Older engines require zinc to protect and eliminate problems with wear- it also helps engines to start more smoothly in colder temperatures. ZDDP (Zinc Dialkyl Dithiophosphate) creates a protective coating on metallic surfaces and is integral for keeping older engines running. MOTUL 20w50 has a very high zinc content at 1800ppm, to ensure your engine is maintained effectively. As many classic cars are put into storage for winter layup, it can often mean they aren’t driven for an extended period of time. This zinc film protects the components of the engine when you’re ready to start your classic up again when Spring comes around.

Another common issue with classic cars can be oil pressure. Maintaining oil pressure is extremely important, as low oil pressure will mean decreased lubrication and will result in more friction in your engine. Oil pressure can drop in your engine if the viscosity has reduced. Oil viscosity is reduced when polymer structures in the oil get broken due to mechanical stress. The resistance to the polymer structures being broken is known as shear stability.

MOTUL 20w50 is formulated with short-chain additives, which ensure that the engine oil has a high shear stability and therefore oil pressure will be maintained throughout the oil service life of the vehicle.