Engine oil

[Simon.Pieman]

A lot of people seem to distrust supermarket own brand stuff, but if its 10w40 semi synthetic bike oil, is it any different to the branded stuff???

Probably yes, but almost certainly not different enough to worry about.
Can any of the people on here relate a story where an engine broke because they used cheap oil rather than expensive oil? I doubt it and I'd bet that most bikers don't know what happens inside an engine when an oil breaks down and stops doing it's job.
If everyone on the forum just used cheapo mineral based Castrol GTX (£16 for 4 litres) for the rest of their lives I bet we'd never hear of an oil related breakdown.