Hi guys

My dad's got the above, he's never get great economy from it, anyway he's just had it serviced, and the mpg has just plumeted, he only gets 30mpg now, he was getting about 35mpg before.

I had a vectra 1.9td8v and now 1.9td 16v and i get about 42mpg from both, i do the same type of journeys as him, i know the sigmun isn't quite as econimical as the vectra but any ideas by why his mpg should just plumet like that after a service?

My guess is they's put in the a thick oil?

(and he drives it, like he's driving miss daisy)