Synthetic oil

[robbie]

I am guessing the answer to this will b e yes, but is it fine to run the 2,5 diesels with Synthetic oil in them??

Just bought one and it is need of an oil change.

[Budgie]

You can but if it's an older N/A that's got over 100k on the clock then I would stick with a good mineral oil or semi synthetic and just change it regularly.

If you do change to Synthetic then drain the old oil, run it with flushing oil first, drain it again and then put the synthetic in there. This will clear out any residue of the old oil and not effect the new one.
You can mix mineral & semi synthetic but once synthetic is in there then you can't mix it with anything else.

[robbie]

I think it is a N/A and has done around 82k so I guess semi synthetic will be best then

Thanks for the info

[Range Rover Blues]

I wouldn't waste your money on Synthetic because it's unlikely to have the correct viscosity for the diesel.  Don't get too hung up on synthetic, the major reason it's used is to extend service life without loosing viscosity but as the oil's secondary job is to clean the engine I prefer to swap it more often.
Using the thinnest oil that is within spec for your engine can have benifits on fuel economy but at the extremes it can shorten the engine's life.