Different brands of oil are not recommended to be mixed, although the importance is that they are of the same grade.

As turbos are so common now (especially on diesels) all Castrol products
are developed for use in turbocharged engines. Obviously the
normal requirement of the oil needing to meet the appropriate
specification for the particular vehicle still applies.

The only caveat is that turbos can be relatively easily modified to
boost performance significantly and any vehicle where a turbo system has
been added or modified needs to be treated as a special case - we would
normally be thinking about Edge Sport 0W-40 or, in extreme cases, maybe
10W-60 for these vehicles.

This offer ends Monday 17th Novemeber.