Technical articles
Knowledge that protects engines

Practical, independent explanations of oil specifications, viscosity, lubrication, engine protection, and automotive fluids.

17 articles 4 topics
Automotive lubricant testing in a modern laboratory

Featured insight

Unbranded engine-oil bottles and a clean engine component illustrating Porsche oil approval selection.
Specifications Explained

Porsche A40, C20, C30, C40 and C40 GT Engine-Oil Approvals Explained

Porsche oil codes identify manufacturer approvals, not just oil thickness. This guide explains the practical meaning of A40, C20, C30, C40 and C40 GT, why two 0W-40 oils may still be unsuitable substitutes, and how to verify the correct approved product for a Porsche engine.

Read featured article

Browse the library

All articles

Specifications Explained A fleet technician inspects an engine oil sample beside heavy-duty diesel trucks.

API CK-4 and FA-4 Specifications in a Nutshell

The American Petroleum Institute launched two new diesel specifications in 2016. The specification criteria were revealed last winter and the first claims can be made starting from December 1st, 2016 so oil manufacturers have time...

Read article
Specifications Explained An engineer inspects a motor oil sample beside a gasoline engine test stand.

API SN Engine Oil Category

In 2010 the American Petroleum Institute introduced a new engine oil category under the name API SN and a new supplemental category called Resource Conserving. The API SN category is an improvement over the API...

Read article
Specifications Explained A mechanic services the wet clutch assembly of a modern motorcycle.

JASO MA and JASO MB classifications

Modern motorcycles usually have the same oil lubricating the engine and the wet clutch. For this purpose most of the time the regular friction modified engine oils are not good enough. To make sure that...

Read article