I have just completed the Diesel Training Course and am working on creating a Stage 1+ for my personal vehicle, a USA market 2013 Volkswagen Passat TDI with an EDC17C54.
EDC17 can be classified as Euro 5 or Euro 6 standard and the AFR calculations are different.
In Europe, this vehicle would be classified as a Euro 5.
In the USA, it is classified as "Tier II/Bin 5 requirements".
Can anyone provide clarification on which AFR strategy I need to use for USA market vehicle(s)?
Hello
Before C64, it was Euro 5
~19:1
The distinction between AFR strategies is not strictly based on whether the vehicle is classified as EU or US, but rather on the emission control architecture implemented in the ECU.
As a general rule:
Euro 5–type systems (typically without SCR/AdBlue) rely mainly on:
EGR
DPF
Euro 6–type systems (with SCR/AdBlue) introduce:
More advanced lambda control strategies
NOx model, and SCR efficiency
For US vehicles (Tier II / Bin 5), the classification does not directly map to Euro standards. Instead, you should identify the strategy by checking the hardware:
If the vehicle is equipped with SCR (AdBlue) → it typically follows a Euro 6–like AFR strategy
If the vehicle does not have SCR → it is generally closer to a Euro 5–type AFR strategy
Use the strategy for EUR5
If it is EUR6, then we have 3.5% too much air, but this wouldn’t cause a noticeable fuel economy impact, nor turbo overload.
Of course, a perfect calculation sounds great, but still a “misfire” of 3.5% wouldn’t cause any noticeable trouble.
And it is better to choose lower norm, than to misinterpret.