BMWDiesel
840d xDrive Convertible G15
340 ch · 2021
Motorway range comparison
Trip mapped at a glance. Charging stops visible, total duration predictable. Caralogy simulation at 130 km/h.
Paris → Marseille · 130 km/h · Caralogy simulation
| 840d xDrive Convertible G15 | P7i | |
|---|---|---|
| Total time | 7h01−27 min | 7h28 |
| Charging stops | 0 stops−3 stops | 3 stops |
| Total cost | 81,93 € | 65,51 €−16,42 € |
Both vehicles drive at 130 km/h. The difference comes from charging stops.
Analysis
Both vehicles drove at 130 km/h for the entire trip. The 840d xDrive Convertible G15 (combustion) makes no stop, the P7i (electric) 3 stops totalling 27 min. Road safety reminder: on a trip of this duration, it is recommended to stop for at least 51 min total (17 min every 2h). The energy cost is 81,93 € for 840d xDrive Convertible G15 versus 65,51 € for P7i.
The official WLTP figures (6,0 L/100km for 840d xDrive Convertible G15 and 16,9 kWh/100km for P7i) are measured on a mixed cycle averaging ~46 km/h. At a steady 130 km/h, aerodynamic drag weighs much more heavily - it grows with the square of speed. Caralogy calculates a motorway consumption specific to each vehicle based on its aerodynamic profile (SCx), weight and power curve - not a uniform correction factor. For this trip, the simulation yields 5,2 L/100km (840d xDrive Convertible G15) and 20,3 kWh/100km (P7i). Full methodology: see the dedicated button above the summary.
On a 200 km round trip (e.g. a weekend getaway), the electric or plug-in hybrid vehicle completes the entire journey on home energy at 0.18 €/kWh - with no charging stop. The time advantage of the combustion car on long-distance motorways disappears entirely, and the economic advantage of electric strengthens considerably.
The cost per kilometre depends on the electricity rate applied to each segment - based on the energy source used at that point of the trip.
| Segment | Distance | €/km | Cost |
|---|---|---|---|
| Paris → Marseillefuel · 2,03 €/L | 775 km40 L consumed | 0,106 €/km | 81,93 € |
| Trip total | 81,93 € | ||
| Segment | Distance | €/km | Cost |
|---|---|---|---|
| Paris → Tournus, A6initial energy charged at home · 0,20 €/kWh | 355 km72 kWh consumed | 0,041 €/km | 14,41 € |
| Tournus, A6 → Valence, A7energy charged at Ionity 213 kW · 0,60 €/kWh | 158 km32 kWh consumed | 0,122 €/km | 19,20 € |
| Valence, A7 → Manosque, A51energy charged at Ionity 213 kW · 0,60 €/kWh | 158 km32 kWh consumed | 0,122 €/km | 19,20 € |
| Manosque, A51 → Marseilleenergy charged at Ionity 204 kW · 0,60 €/kWh | 104 km21 kWh consumed | 0,122 €/km | 12,70 € |
| Trip total | 65,51 € | ||
How many kilometres do you recover depending on the time spent at the charger? Comparison at nominal peak power.
| Charging stop duration | BMW 840d xDrive Convertible G15 | Xpeng P7i |
|---|---|---|
| 5 minutes | - | ~62 km |
| 10 minutes | - | ~124 km |
| 20 minutes | - | ~247 km |
| Full session 10 → 80 % | - | ~276 km24 min |
Replace one of the two with an alternative from the same segment
340 ch · 2021
282 ch · 80 kWh · 2023
The advantage comes from the combo real range + charging speed. On Paris → Marseille (775 km at 130 km/h), the 840d xDrive Convertible G15 arrives in 7h01 with 0 charging stop.
WLTP consumption does not reflect motorway reality. Aerodynamic drag grows with the square of speed, so real consumption is 15 to 25 % higher than WLTP combined. Caralogy calculates a highway consumption specific to each vehicle based on its aerodynamic profile (SCx), weight and power curve.
Total time = driving time + charging time. Driving time is calculated at an average speed of 130 km/h on the motorway (adjustable). Charging time is calculated based on the real power curve of each vehicle, respecting the optimal 10 → 80 % range and the maximum power accepted by the chargers on the route.
No. The displayed cost covers only the energy consumed during the trip: kWh × energy rate, with a mix of home charging and DC fast chargers. Battery wear is a long-term ownership cost, not a trip cost.
Electric: 81,93 € (840d xDrive Convertible G15) and 65,51 € (P7i). An equivalent petrol SUV (~8 L/100 km) would cost about 115 € in motorway fuel. Electric costs less in energy but adds charging stops.