What is the difference between a 5W40 and a 5W30 oil?

We often see the references 5W40 and 5W30 on the cans of motor oil in store. But what is the difference between these two denominations? Which oil relates to what type of engine?

The 5W40 oil is designed for powerful cars, sports car engines, for city driving, for small trips, for recent engines. It is a totally synthetic oil.

The 5W30 oil is also an oil that is made for modern car engines. The main difference is that it is an obligation for vehicles equipped with a particle filter, ie for diesel engines. It is however compatible with the petrol cars.

Both oils are perfect if you have a dynamic driving, with frequent stops and restarts. Cold start is facilitated. Emptying intervals can be extended, up to 30,000 km for diesel and up to 15,000 km for petrol.

Note that legally you must empty at least once a year or every 15,000 km.

Best 5W40 oil:

The Castrol EDGE Turbo Diesel 5W-40 5L is an engine oil which has a great lubrication power, it exerts an excellent protection on the parts of the engine. It is suitable for motors with high speeds. With its great fluidity, it optimizes engine performance and responsiveness.

Best oil 5W30:

The Total Ineo ECS 5W30 5L engine oil offers one of the best prices on the market. It is an approved oil for Peugeot and Citroën cars. It is an ideal oil for HDI engines since it is low emission. Thus it does not clog the EGR valve or the anti-pollution system. The life of the engine is increased, whether we are in summer or winter.

Refer to the manual of your car to find out which oil is best for your engine.