My e46 320Ci seems to be using an awful lot of fuel. I put a tenner in the other day, which showed up as 59 miles on the computer – normal enough. But after a quick 3 mile trip into town and back, it had used 18 miles of this. Not normal! Then a few days later, we were cruising along the motorway at 70, computer showing 20 miles of fuel left, but as we pulled off the motorway and drove around a few small roads and around a retail park, I watched the numbers tumbling away.. it went from 20 down to 5 over just a mile or two! So we put £10 in the car (back up to 60 miles left), and watched the ‘miles left’ reading on the computer as we drove back through the same streets and back onto the motorway. It was fine, used only 5 miles of fuel all the way back home (which is about 5 miles!).
So what have I got here, a malfunctioning trip computer, or something more sinister and engine related?
When I first got the car 18 months ago it was using average of 30mpg. I have noticed that dropped to about 26mpg in recent months, so something could be up with it.
Would a OBD2 thing and that Torque program be able to read whether the car is running too rich or not?
cheers for any help.