Poor mileage

Hi!
Have an issue again with rubish mpg. This time on a '97 300tdi auto and manual FIP.
On the clock 240630km (~150000miles). Running BFG AT 245/75x16 on 8 spoke modulars. MPG about 20.
What i've done:
-removed cat
-blanked EGR
-cleaned the sedimenter
-new fuel filter
-new lift pump
-changed the FIP, checked static pump lift for 1,4mm with a dial gauge
-new timing belt, timing ok
-new injector nozzles, opening at 200bar with "POP"
-cleaned the intercooler
-checked for damages on boost hoses, all ok
-boost pressure 0,9bar
-made a cylinder compression test; 26, 28,5, 28, 27,5bar
-checked valve clearnace, all at 0,20mm
-checked all fuel lines for leaks
-new air filter
-new engine oil and filter

No noticeable black smoke except at night in my rearview mirror in lights on a car behind me on accelerations.
No blue, grey or white smoke either.
No oil consumption or coolant consumption either.
The autobox shift's smooth, the torqueconverter locker lockes at 78km/h. Oil and filter in autobox is new, also.
Well, with no roofrack and bullbar, no towing, no hills, no citiy, on country roads 20mpg or 14l/100km is way toomuch, i think.

Any ideas? Did i miss something or did i something wrong?
Thanks in advance for your replyes

Depends how you drive.
If you have a 'yob foot' then it will get **** mpg. My 300 was regularly returning 30mpg with mixed driving from town, motorway and some slight off road stuff.

Either that or empty the 2ton of crap out your boot.

You won't get better than that.

1) it's an auto

2) slightly taller tyres are making it
a)work harder. b) not giving true MPG figures

Don't forget a Discovery is a 2100Kg car and by no means a light thing to propel around the roads. Looking for economy, buy a Smart car, apart from that, looks like you hve done everything else possible.

If I read you correctly, your lock up speed is about 10% wrong and probably explained by the tyre sizes which are also about 10% wrong on their rolling diameter. That would mean you are getting about 10% better mpg than you think i.e 11.6l/100km and that is not too bad for the auto.

boost is a bit low, should be just over 1bar.. but it could be an inaccurate gauge.. might explain the unburnt fuel on accel though.

has someone fiddled with the fuel pump?

10% increase on 20 mpg is not a lot.

Hey! Sorry, forgot to mention, measuring with GPS and not with odo.
Tomorrow i'll try to raise boost pressure by shortening the rod on the wastegate acutator.

compadre said:

Hey! Sorry, forgot to mention, measuring with GPS and not with odo.
Tomorrow i'll try to raise boost pressure by shortening the rod on the wastegate acutator.

Click to expand...

i wouldn't be doing that. it's way more likely a leaky pipe/connection/gasket or inaccurate gauge.

plus it won't change your mpg.

Ok, so i'll try another gauge first.

compadre said:

Hey! Sorry, forgot to mention, measuring with GPS and not with odo.
Tomorrow i'll try to raise boost pressure by shortening the rod on the wastegate acutator.

Click to expand...

Does your gps measure cartesian or as crow flies? Use odometer and recalc for tyre size. 22mpg is about right for your car

Sorry, don'tknow cartesian and crow files. Im measuring with a car navigation such as IGO Primo and with a second one wich is actually a dashcam with built in GPS.
The are independent from each other and give both the same numbers.
With 245/75R16 tires the odo is allomost even with the GPS. Difference under 1%.

About my driving style i can say im no racer or not have a heavy foot