I Want to make changes in routing algorithm


Hello, I’m new to graphhopper and open source projects. Currently implemented algorithm gives optimal time travel path. I want to calculate optimal Fuel Path.

1.So now I want to change the edge weights(time to fuel). Which part of the code I need to focus on.
2.For calculating Fuel consumption for each edge, I need to use elevation along the road. So which api I need to use. Please Help me.