What oil should I put in?

Absolutely.

Still worth checking the oil though, even if you have an engine that doesn't use any.
Mind you, I'm from an era when it was completely normal to check the oil level in the engine.
As there is no oil level check in a Playstation, the routine isn't getting taught to young drivers these days!

I had an Alfa mechanic tell me that the TS engine is designed in such a way that it sprays oil onto the piston crowns to cool them, and the oil evaporates or vaporises on contact with the piston. He said that it reduced the emissions. Don't know whether that is true or a load of cobblers.

My dad has an Audi A6 2.4 V6, which he has had from new. He uses more oil than me, and that is fully synthetic at about £15 per litre. He went back to the dealer because he thought something was wrong with the car and they told him to read the manual. It says that it is only a problem if it uses more than a litre every 1000 Km (that is about every 600 miles).

Some cars are meant to use oil.

There are oil jets directed onto the underside of the piston.
Not unique to the TS engine though.

I agree if you don't know whats in there get a flush and change the filter..

Yes I know exactly whats in mine, and have some more on the way now from shop4parts.

My issue was that it seems my 2.0L tspark was specced 10w60

and the garage put 10w/40.

I'm sure its ok, I just think I'll go for 10w/60 next oil change..

When discussing oil brands, it's always worth reading this article first The surprising truth about motor oils

While you should never neglect checking oil levels and performing oil changes - and always (on older cars) check for mineral v synthetic - pretty much everything else is marketing.