I have been getting about 25 mpg since buying my '5 in Sept 08. The engine runs like a dream, starts first pop and never misses a beat. I have checked the air filter and this appears to be new. I understand that a dirty fuel filter will also affect mpg, but I have no idea where it is or how to change it. I feel that a service may be the answer, at least it can’t hurt, so here come the questions :-
MPG probs - I expect 30mpg, so if I were you I’d give it a service and replace these parts, then see how it goes… Could be down to cold weather & short journeys…
A badly adjusted rear brake will also cause the brakes to bind a bit, increasing fuel consumption. Check one or more of the rear wheels doesn’t feel too warm after a run.
A thermostat thats stuck open might also increase fuel consumption; a giveaway is an engine that never seems to warm up, except in traffic (ie. heater runs cold as you head onto the open road).
Air filter wouldn’t hurt.
On a 1.6, typically you should be expecting to get 30-35mog without much effort, and 40-45mpg if driving carefully.