What Engine Oil For Mk7 Fiesta

[kabz77]

Good Morning Gents

I need your help, I'm trying to figure out the difference between engine oils.

My car is due for a service and Ford have told me that I should use a fully synthetic 5W30 rating oil.

I was planning on using Castrol Magnatec fully synthetic 5W30

I wanted to know what does the 5W30 mean, I've seen bottles at 10W40 etc

I've been offered a free 5L bottle of Mobil FE 5W30 semi synthetic oil, will this work on my car? What is the difference between semi and fully synthetic?

A friend has said that I could also use 10W40 as this oil is better in warmer conditions.

Any help and advice will be greatly appreciated.

Thank you

[mintalkin]

First number is the viscosity(thickness) when cold, the second number is the viscosity when hot,

Regular engine oil comes from the ground. Synthetic oil also comes from the ground but is then changed on the molecular level in the lab.

ford motors can be sensitive to what oil is put into them so to avoid things like sticky valves, go with what ford recommends.

[kabz77]

Mintalkin - thank you Sir for your prompt reply. Gonna buy the Castrol Magnatec 4L from Tesco at £24 (cheaper than Halfords and Asda)