There is another school of thought that says (once warm) that during the break in period you should drive the car like you stole it.

The reason being is to allow the piston rings to correctly bed into the bores. This is done theoretically before the bores have a chance to glaze.

It is said that by not doing this you are more likely to suffer oil loss problems, which incidently you read an awful about on forums such as this.

I'm on my second PD engined TDI at the moment and both of them have only ever needed minimal topping between changes.

I say all this theoretically as it is a policy of mine never to buy a brand new car and that if I did, I'm not sure that I would actually thrash a new engine anyway...

I think it is a case of the internals being machined to such high tolerances these days that a thrashing will do little harm the bearings which used to be the main reason to 'run' an engine in. The bores and rings however benefit highly from the increased pressures of a thrashing especially when the engine is new.

A case of being cruel to be kind if ever I've heard one.

For a more plausible and informed explanation of this go to tdiclub.com and do a search.