MK8 Ecoboost Oil

[brilldoctoe]

Just got back from taking my 2018 1l 125bhp mk8 fiesta for its 4th year service at an independent garage (having previously only taken it to the main dealer), to discover that they have used 5w30 oil, rather than 5w20.  Having spoken to them about this, I was informed that it doesn’t make a difference in the UK and shouldn’t cause any issues, something the Ford manual and for dealer seem to disagree with.

 

Is this likely to cause long term damage to the engine, or is it likely to make no difference?

[unofix]

1 hour ago, brilldoctoe said:

Is this likely to cause long term damage to the engine,

Probably. The ecoboost engine is a sensitive beast. What type of 5W30 did they use, fully synthetic, part synthetic or some unknown spec ? 

[brilldoctoe]

The invoice says fully synthetic but doesn’t specify which brand

[Luke4efc]

It's probably generic stuff not made to Fords spec. They probably have a big 200L drum of it in the back.