Just to clarify a few wrong points in this thread:

The 'W' stands for Winter and it relates to the first number in a multigrade oil. (Also it doesn't mean 'weight' as in Fast and the Furious movies)

i.e. 10W-40 means a it is as viscous as a SAE 10 grade at lower temps (i.e. Winter) and is a SAE 40 grade at operating temperature (100 degrees).

A 5W can be pumped around your engine at a lower temperature than a 10W, a 0W at a lower temperature than a 5W.

The higher the number, the higher the viscosity. So putting in a 70 grade is like having thick honey in your engine compared to a 40 grade.

If unsure stick to your manufacturer / tuners recommendations.

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[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]