Modern cars measure injector timing for instant fuel flow and then average that over time. Most have a correction factor that can be adjusted, and some automatically adjust that based on the longer term use over a few full tanks. For example this is how to adjust it manually for a previous model BMW 3 series: https://www.e90post.com/forums/showpost.php?p=17714563&postcount=7
On all the cars I’ve had which display fuel consumption (I think about six) the accuracy has been all that’s required for any practical purposes, and of course for noticing any changes which might indicate a problem.
Whenever I’ve checked with a fill-up of known volume and a manual calculation they’ve been accurate to within one mile per gallon at least.
We’re talking about different worlds. On an aircraft the amount of fuel on board and the rate at which it’s being consumed are extremely important to safety – so you either know both to a high degree of accuracy or you operate with such large margins as to render it irrelevant. The same is not true of a car.
A DPF is of no use on a constant high power engine, flying airborne. It has value only in urban environments. An EGR would be just another high failure rate component; see the VW (and many others) ECU software cheat scandal and the EGR issues around that.
Can you confirm if EGR and DPF are actually removed?
I’m pretty sure CD155 engine doesn’t have EGR. For DPF I’m not sure but I guess that it doesn’t have it either. I believe AE300 is the same in that sense.
I think I remember you had a coolant leak at the beginning of your Da42 ownership. IIRC it was bad routing of the flex tube. Did anything like that happened again?
The leak was caused by broken clamp and hose slipped from the attachment point. Hasn’t happened again but I had these engines (CD135) for some 2 years after that and replaced them with CD155.
Can I do it under CS STAN or do I need EASA major mod approval ? 
You need an accurate fill-up 
However, to make it work properly you need to link it to a GPS so it can display the LFOB, so you need to install perhaps a KLN94, GNS430…
That’s an idea and will be unique
Will you help me determine the K-factor ? :-)
Nothing stops you installing a Shadin totaliser on your VW
@Peter
The turbine / fuel flow meter is a good technology it seems.
Thank you for your help and nice input.
@Emir
My bottom line was provocative :-)
Can you confirm if EGR and DPF are actually removed ? I think I remember you had a coolant leak at the beginning of your Da42 ownership. IIRC it was bad routing of the flex tube. Did anything like that happened again ?
As I’m struggling with the injector, it appears a significant value called « quantity deviation » which is the quantity of gas added or removed from the nominal value, calculated by the engine for each injector, in order to have a stable engine.
During maintenance, do you have such parameters available ? Are injectors to be replaced on timely basis considering the high pressure they work with ?
