Similar CO₂ emissions for full vs. partial truckloads — why?

Question

I'm analyzing freight transport emissions and encountered a counterintuitive result: transporting 27 tonnes in a single full-load trip produces nearly the same CO₂ emissions as three trips carrying 9 tonnes each (same distance, same vehicle type).

I would expect the full-load scenario to be significantly more efficient. Is this due to how emissions per tonne-km are calculated, or does truck fuel consumption not scale linearly with load?

Any clarification would be appreciated.

Answer 1

Hi, I think good question but you need to explain how you modeled this - if it is in ecoinvent, then this is the expected result, as everything just goes by ton-kilometer in ecoinvent. But as you say not the realistic impact.

Best wishes,

Andreas