SAE 5W-30 and always has been.

 

Another what oil discussion!

The Opie website actually recommends 5W-20 for a 2012 Mk3 ST3.

If you check the Castrol website, it also shows 5W-20.

https://www.castrol.com/en_gb/united-kingdom/home/car-engine-oil-and-fluids/motor-oil-and-fluids-finder.html?page=recommendedProducts&id=6740fb60b386dfa032ec1a1216d45813

 

Ford PTS (newer version of ETIS) recommends:

Engine Oil

Viscosity​	Specification​
SAE 5W-20 ¹​	Material: Recommended: Ford-Castrol Magnatec (WSS-M2C948-B)​
SAE 5W-30​	Material: Recommended: Ford-Castrol Magnatec (WSS-M2C913-D)​

¹ This oil is recommended for vehicles with particulate filter

 

This has been discussed so many times. There is Ford documentation on this site somewhere in one of the many threads that Ford changed the recommendation to 5W-20.

 

Thread 48373928273 about this

 

Thank you order has been changed.

Now I've found a massive oil leak so it may be going back