Just had my Focus serviced and the list the oil used as Shell Helix 5W30 semi-synthetic - I thought the 1.0 Ecoboost required 5W20, is this correct and will the 5W30 cause any issues?

thanks, Mark

My belief is that the thin oils they are specifying are all about producing very low emmissions rather than protecting the motor long term. The 5w-30 will be a bit thicker and cling better when its hot, but be exactly the same when its cold. I'd be tempted to use the 30 anyway. i'd say nothing to worry about.

One thing I have learned about oil though, everyone who has an opinion is convinced they are right. And that includes me!!

The 1.0 ECOboost requires a 5W20 engine oil that meets the Ford WSS-M2C948-B specification. This is the only type of oil that is allowed for this type of engine!

Shell Helix 5W30 semi-synthetic does not meet the Ford WSS-M2C948-B specification and apart from the specification it also has a different viscosity. The person that used this type of oil did clearly not look at the requirements for this type of engine at all.

Using incorrect engine oil on a 1.0 ECOboost can be a serious problem. This engine has wetbelts (timing belts that are mounted inside the engine and run through the engine oil). There is a wetbelt between the crankshaft and the camshafts and another wetbelt between the crankshaft and the oil pump. Incorrect engine oil can potentially affect the rubber material of the wetbelts. Using an incorrect type of engine oil (even for a short period) can start a deterioration process inside the wetbelt material and on the longer term cause premature failure of the wetbelts.

The only way to make sure that the integrity of the wetbelts is not affected by the incorrect engine oil is by replacing the wetbelts.

 

Interesting. Has anyone ever had a belt go through wrong oil?

 

I didn't notice the OP had used semi synthetic I must admit, I would never use that. But fully synthetic that meets the criteria with a slightly higher viscosity wouldn't worry me at all.

just checked with the garage and they are going to drain the oil and replace with 5W20 - for some reason my car shows up with the wrong engine on their system

Premature wetbelt failure on a 1.0 ECOboost is not uncommon at all. This can have several causes:

* Incorrect engine oil.
* Not respecting the service intervals. The Ford WSS-M2C948-B engine oil is known to deteriorate quite fast (and can even form a sludge). Especially when the car is often used for short distances or in case of low annual mileages. These conditions require a reduced service interval.
* Performing an engine flush. There are still idiots (including garages) that think this is a good idea.


In case an incorrect engine oil is used by a professional garage you should have the engine oil and filter replaced as soon as possible and demand a written and signed statement that the garage in question is responsible for future premature wetbelt failure.