diff --git a/scripts/build_transport_demand.py b/scripts/build_transport_demand.py
index f6ff7b3e..a052581b 100644
--- a/scripts/build_transport_demand.py
+++ b/scripts/build_transport_demand.py
@@ -80,7 +80,7 @@ def build_transport_demand(traffic_fn, airtemp_fn, nodes, nodal_transport_data):
     )
 
     # convert average fuel efficiency from kW/100 km -> MW/100km
-    eff = nodal_transport_data["average fuel efficiency"] * 1e3
+    eff = nodal_transport_data["average fuel efficiency"] / 1e3
 
     return (transport_shape.multiply(energy_totals_transport) * 1e6 * nyears).divide(
         eff * ice_correction