diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index 4bfbc9c0..eb37130f 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -1561,14 +1561,7 @@ def add_land_transport(n, costs):
         )
 
     if ice_share > 0:
-        if "oil" not in n.buses.carrier.unique():
-            n.madd(
-                "Bus",
-                spatial.oil.nodes,
-                location=spatial.oil.locations,
-                carrier="oil",
-                unit="MWh_LHV",
-            )
+        add_carrier_buses(n, "oil")
 
         ice_efficiency = options["transport_internal_combustion_efficiency"]
 
@@ -3339,7 +3332,7 @@ def add_enhanced_geothermal(
     orc_capex = (
         costs.at["organic rankine cycle", "investment"]
         if not snakemake.params.sector["enhanced_geothermal_optimism"]
-        else 0.
+        else 0.0
     )
 
     # cost for ORC is subtracted, as it is already included in the geothermal cost.
@@ -3348,7 +3341,7 @@ def add_enhanced_geothermal(
 
     egs_potentials["capital_cost"] = (
         (egs_annuity + FOM / (1.0 + FOM))
-        * (egs_potentials["CAPEX"] * 1000. - orc_capex)
+        * (egs_potentials["CAPEX"] * 1000.0 - orc_capex)
         * Nyears
     )
 
@@ -3357,11 +3350,7 @@ def add_enhanced_geothermal(
     ).all(), "Error in EGS cost, negative values found."
 
     plant_annuity = calculate_annuity(costs.at["organic rankine cycle", "lifetime"], dr)
-    plant_capital_cost = (
-        (plant_annuity + FOM / (1 + FOM))
-        * orc_capex
-        * Nyears
-    )
+    plant_capital_cost = (plant_annuity + FOM / (1 + FOM)) * orc_capex * Nyears
 
     efficiency_orc = costs.at["organic rankine cycle", "efficiency"]
     efficiency_dh = costs.at["geothermal", "efficiency residential heat"]