Just interested

[goddo]

Forgive me for asking a question which has probably been discussed to death many times.
A 4.4litre SDV8 has a TDV8 engine if I've been informed correctly.
Why don't they just call the car a TDV8 in the first place, or is there some licensing law (say with the USA) that prevents this happening?
I also understand that the SDV8 engine does exist but in comparison with the TDV8 it has less grunt. I'm confused!! Can someone put it in plain English or is it me not getting the picture?

[Scrump]

I thought the SDV8 was so called to indicate it was an improved version of the engine compared to the TDV8. Marketing.

[Bobupndown]

'SD' is normally the more powerful output above the 'TD' in landrover speak.