Your car's own handbook should also tell you what oil to use, I personally don't like the way halfords do it, as long as your car needs eg 5w30 part synthetic then don't be confused with the Halford branding "ford oil/BMW oil" it can put you out of pocket. I bought the halfords "Ford" oil purely because it was the right type (ie 5W30 Part Synthetic) and the cheapest, I don't own a Ford.. :)
And some motor manufacturers require their own approved oil. I have a New Mercedes which uses 5/30. But it has to state on the can it’s MB approved. Not any 5\30.