Highway: Electric cars 44% cheaper than diesel

On the highway, we observed the energy consumption and rapid charging of an electric vehicle. The results are clear: it wins compared to thermal engines. 

Christmas 2022, we took the wheel of one of the most expensive cars in the Mercedes-Benz lineup. Indeed, the EQS 450+ easily surpasses the six-figure mark. But our Mercedes EQS review is clear: it’s a true technological masterpiece. And this electric car has a quality despite its weight of a pachyderm (2.5 tons) and its limousine length: very low energy consumption.

How much does an electric car cost on the highway?

However, does the challenge of the highway and the charging price penalize it? Because we know that fast charging is much more expensive than at home. The price per kWh is often above €0.50, compared to €0.174 according to regulated EDF tariffs. But this does not account for the fact that Mercedes-Benz is part of the Ionity consortium, the very present ultra-fast European charging network in France. 

Thus, the brand offers advantageous prices for all customers, with a rate of €0.35/kWh, versus €0.69/kWh for others. It is necessary, however, to subscribe to one of the Mercedes me charge plans, the “M” at €4.90/month to be eligible. For one long trip per month, this amount must be added to the total cost.

Let’s do the math. We traveled 750 kilometers with the Mercedes EQS 450+, using 162.6 kWh of battery charge according to our measurements. At the current rate, this costs €56.91 for charging, plus €4.90 for the subscription. Our highway trip therefore cost €61.81.

Electric is 40% cheaper than diesel on the highway

Nearly 62 euros, is it expensive for a car? We can compare with an equivalent thermal model. For that, let’s consider the Mercedes S Class 400 d, whose 330 hp power is almost identical to our EQS. Its purchase price is actually higher, which, with the 2023 bonus, is €138,490, exceeding the €135,850 of the electric. But let’s go back to energy costs.

The combined consumption of the Mercedes diesel is 6.7 l/100 km. On the highway, we can round to 7 liters/100 km. On our trip, the stations currently display diesel at an average of €2.10/liter. With these parameters, the 750 km require 52.5 liters, totaling €110.25 in fuel.

The difference is therefore clear between electric and diesel: almost €50! In other words, the Mercedes EQS 450+ is 44% cheaper than the S Class on the highway. QED, based on this experience. Because the price will obviously vary depending on the model chosen, the charging station rate, fuel price evolution, and the efficiency of the thermal equivalent.

Also read: Tesla Model Y, how much does electric SUV charging cost?