Distance is different for Car+Fastest on graphopper with own CarFlagEncoder+Fastest

Hello everybody,

we implemented the „CarFlagEncoder“ and receive for the weighting = FASTEST a different result for the following coordinates:

Start: 51.002594, 11.113369
End: 52.520409, 13.500957

Thats the result we got:
Our Distance = 295,70 km

And that is the result of:
Graphopper Distance = 316km


Does anybody has a hint what are possible differences or factors for the various results?

We want to get the same results like Graphhopper…