D40 Bad fuel efficiency

[Dakov]

Good day Team,

Here for a quick enquiry regarding my D40s recent bad fuel efficiency.

I recently replaced the turbo charger and I'd say its working better than ever. But immediately after doing so I noticed a change in the fuel economy of the vehicle. So I did a small test by feeling up the tank up to a 1/4 and drove for about 11 kilometers. Up to this point my gauge pointed to just below 1/8 of the tank, that is below a half of a quarter tank and slightly above the empty tank mark. Very unusual when compared to the recent past.

Is this a normal occurrence and has anybody experienced this and what did they do to get it fixed?

Are there issues that could be causing this? Is there anything I can do to rectify it?

Thanks

 

[Old.Tony]

Couple of things at play here.

1) Reset the fuel map. Easiest way is to get your radio PIN, write down your tripmeter figures if you're using them then pull the battery negative lead off the battery and go step on the brake pedal. You can immediately go and reconnect the battery and take the car for a gentle drive, don't use full throttle, but make sure you drive for about 15 minutes (no less). Find somewhere safe to stop, pull over and turn off the engine to save the new fuel map.

2) The fuel gauge is about as accurate as the weatherman. Don't rely on it for precise readings. I always fill my tank and write the km (odometer and Trip A meter) on the receipt which I then calculate from using a simple formula. First, reset the Trip A meter (long press the right hand adjuster while Trip A is showing). Then divide the result you wrote down for Trip A by 100 - so "472.8km" becomes 4.728 and this is your divisor. Grab the fuel you've put in - let's say it was 55 litres - and divide by that divisor, so in this example you'd put 55 / 4.728 into your calculator and press the = button to get 11.632825719120 or just say 11.6 litres per hundred km (LPHK). This ONLY works if you reset the trip meter after each fill AND you fill the tank to nearly the same place (either 'first click' or until you see fuel in the neck, whichever you want).