- Dec 16, 2020
- So. Calif.
Yes, they are. The OEM makes this call, not the oil suppliers. Here's what it says in VW 508 00, section 1, Scope:
Engine oils as per this standard are service engine oils with a lower ash content. They meet the requirements to realize extended oil change intervals when used in the aforementioned Volkswagen Group engines. Due to their reduced HTHS viscosity, less energy is needed to pump them, they have exceptional fuel-saving properties and are distinguished by high thermal resistance, as well as optimized soot capacity. Due to their reduced HTHS viscosity, the engine oils described here are not backwards compatible and can be used only in specially approved engines (no universal engine oil).
The bold is not mine - this is how it is written in the specification document.
Ok, I stand corrected. However, it was a well known oil producer that states "May not provide adequate protection" when referring to use in engines not made to use 508 and the last sentence makes my case (not backwards compatible and can be used only in specially approved engines (no universal engine oil)).