2.8V6 poor economy
First a short intro - after many years of Audi ownership (Coupe/fast saloons), a growing family has lead to the need for a Galaxy (I'm 6'5" and we can't all 5 fit in an A6). Negotiations with SWMBO ended up with us getting a '96 2.8V6 as no way was I dropping much below 100bhp/100kg :-)
Over the last year MPG has been much as expected, but for the last couple of months it's been way down - e.g. 16 on journeys I used to get 28+ on. This has been accompanied by an 'odd' smell from the exhaust (not burning, not sulphur, just 'odd').
My usual garage has run diagnostics which check out OK, and they are now officially bewildered! They've suggested more thorough diagnostics by the guy they refer such cases to, but I thought I'd first see if anyone here has come across a problem like this - or has a theory as to what may be the cause.