Citroen C5 2001 estate

[caretaker]

I have just brought an old car a Citroen C5 estate 2001 and was wondering what the letters on the rear are, HDi, tell me if I'm wrong but D=diesel, I= injection but what is the H stand for.
Reg

 

[carlb40]

http://en.wikipedia.org/wiki/PSA_HDi_engine

 

[Phil Pascoe]

Horrible.

 

[RossJarvis]

I had a Citroen XM (last of the great mad citroens) This was the one before the C5 and the engine was not particularly good. It had by far the best seats of any car I've ever had and unlike the rest of the vehicle, they worked too!!

 

[nev]

I always thought H was shorthand for the famous Gallic shrug of non committal