Advanced routing // consumption model for truck


I’m trying to use the consumption model and to adjust its different parameters in order to include the API into our application.
I have some trouble with the consumption model for truck as the consumption result is quite far from our datas.
Starting point : Bourg saint maurice (France)
End point : les Arcs 2000 (France)
Diesel truck (weight : 41t)
consumption : 30 l/100 km at 60 km/h
acceleration efficiency : 0.12 (everything else is 0.3)
The consumption I was expecting (extracted from our datas from a real truck on the same itinerary) was around 24l. The result I’ve got from TomTom is around 58 l (which is more than double compared to our real data).
Do you have any idea where is my mistake as I’m quite surprised by the diff ?


Can you post a request that you are using?
Cause I’m trying to reproduce this and got a ~26km route with consumption of ~8 literes.

please find below my request :

You just have to put your API key and run it. (the consumption result was 78 ish l)

This is interesting: reversing the start and end points gives fuel consumption of ~27.54 l

Is it very uphill on one way and downhill during the return journey…

Yes, the road is going up a mountain. The starting elevation is around 750m and the end is around 2000m.
For the downhill consumption, our truck consumes around 2l (but it was empty so only weighted 20000 kg). Please note that I’m not sure the consumption tracking software of the truck is that accurate going downhill (I think the value is quite low) but it should not be above 10l for the return trip.

Some basic calculations show that lifting 41 tons by 1292 meters requires ~519MJ. Then taking density and uphill efficiency gives ~48,3 literes.

So we assume that uphill efficiency parameter is a way too low.

I’m modified the request as adviced.

Here is the new request :

The consumption is still too high : 42l (but there is progress).However, the travel time is ok (If my datas are correct, the truck got up the road in 25 mins and the estimated travel time from the API is really close to that value).

But I do think that an uphill efficiency of 1 is not realistic…

Setting all efficiency params to 1 gives ~24 literes.
So I think that all other params should be adjusted.
But still 24 literes sounds like hard to achieve.