Neither too fluid nor too viscous: a mechanic's trick for choosing the right oil for your car and avoiding engine breakdowns

Choosing the right oil for your car seems like an easy task. Or not? A simple mistake can cause a serious breakdown or even damage your engine. From the Talleres Ebenezer TikTok account (more than 265,000 followers), they offer some tips to ensure you never make a mistake again when changing your oil : “Did you know that if you use a very viscous oil in your car, you can lose lubrication, raise its temperature, and damage the engine internally ? And if you use one that's too thin, you can even lose oil pressure and damage your car? The viscosity of the oil is very important for the engine,” explains mechanic Juan José in one of his latest videos.

And why is the manufacturer's recommended viscosity so important? "In the past, engines had more clearance and much thicker, mineral-based oils, and nothing was a problem. But now, even the oil has to meet certain requirements for particulate filters and the low fuel consumption it's now estimated to have. Engine expansion and preparation are tailored to a specific type of oil ," the expert comments.

The viscosity of multigrade oil, the most commonly used type today , is indicated by the two numbers on its label, separated by a 'W'. The first value is its cold fluidity (hence the 'W', which stands for 'winter'). The higher the number (5, 10, 15, etc.), the more fluid the oil will be when cold, which is when the car is started . The second value indicates its hot fluidity, hence the higher number (20, 30, 40, etc.).

The key lies in the viscosity of the oil when our car starts up: "You can't have a higher consumption and then add a more viscous oil ," the mechanic recommends. "That will prevent the oil from flowing where it should . It will lower its speed, it will become hotter due to the greater friction the engine will experience, and it will experience greater internal wear ," he warns. You'll notice, in short, that the engine will have a harder time starting. So remember, the higher the number, the more fluid it will be.

But at the same time, you shouldn't use one too fluidly : "You can even lose oil pressure, because it moves much faster through the gaps it has to pass through, passing more oil, and that pressure can drop. This lack of pressure can strain the most delicate and highest areas, such as the turbo ," the mechanic concludes. If in doubt, always consult the vehicle's manual and the manufacturer.