What is the best solution? Electric car built on a dedicated electric platform or electric car built on a conventional platform based on thermal propulsion? Although the BMW i7 and Mercedes EQS luxury electric limousines follow completely different solutions, they are very similar at least on paper.
Photo: Auto motor und sport
With the EQS, Mercedes wanted to build an electric equivalent of the S-Class. The top version (except AMG) is the Mercedes EQS 580 4Matic and costs 135,529 euros. The new BMW i7 in the top xDrive60 version is priced almost identically: 135,900 euros.
CLAR conventional BMW platform vs EVA Mercedes dedicated electric platform
But the two models are very different. The BMW i7 is actually the same with the new BMW 7 Series with plug-in hybrid drive because the new 7 Series is no longer available in Europe with petrol engines without a hybrid system. Basically, the BMW i7 and 7 Series use the exact same platform (the latest version of CLAR platform – cluster architecture) and body.
Instead, the Mercedes EQS uses an original platform and body designed specifically for electric propulsion (EVA platform, used also for the EQE, EQS SUV and the future EQE SUV). This means in particular a low aerodynamic coefficient and very short front and rear overhangs which have allowed for a very generous interior space.
Similar energy consumption, slight range advantage for Mercedes
With a two-volume body and generous tailgate, the Mercedes EQS has a Cx of only 0.20 while the BMW i7 with conventional design and three-volume body has a Cx of 0.24, also competitive. Normally, lower Cx means lower fuel consumption. Especially at speeds above 70 km/h, aerodynamics play a crucial role. So far, however, official WLTP data shows no significant differences. The Mercedes EQS 580 4Matic consumes between 18.2 and 21.3 kWh/100 km and the BMW i7 xDrive60 between 18.4 and 19.6 kWh/100 km.
Similar energy consumption means comparable range but with a slight advantage for Mercedes.The BMW i7 xDrive60 which is the only electric version available has a WLTP range between 590 and 625 km. In contrast, the Mercedes EQS 580 4Matic can cover between 582 and 679 km between two charges. However, the EQS 580 is not the most efficient EQS, as the EQS 450+ single-motor version with the same large battery of 120 kWh gross (107.8 kWh net) can even go 770 km without connecting to the charging station.
The BMW i7’s battery has 101.7 kWh and because the higher aerodynamic coefficient, we expect it to fall short of the EQS’s range. The first comparison test will clarify which model goes longer without charging.
Instead, we have almost perfect parity in battery charging speed. The BMW i7 charges with 195 kW at DC stations and the Mercedes EQS with 200 kW. So, the EQS battery charges from 10 to 80% in 31 minutes and the BMW i7 in 34 minutes. At AC stations, the BMW i7 charges with 11 kWh in 9 and a half hours while the Mercedes needs 10 hours.
Which is faster?
The BMW i7 xDrive60 has a slight power advantage over the Mercedes EQS 580 4Matic developing 544 HP compared to 523 HP. The BMW achieves a higher top speed of 240 km/h compared to 210 km/h for the Mercedes. But the Mercedes’ higher torque of 855 Nm compared to 745 Nm in the BMW gives the Mercedes faster acceleration from 0 to 100 km/h: 4.3 s instead of 4.7 seconds in the BMW.
Both models use permanent magnet synchronous motors (PSM). These motors operate with low energy consumption when their full power is not needed. However, BMW’s motors are direct current excited and do not contain rare earths, while Mercedes uses – admittedly to a small extent – expensive metals in its motors. Therefore, BMW has a small environmental advantage.
Big batteries also mean big weight. The Mercedes EQS is even longer than the long version of the S-Class. But at 5.32 metres, the Mercedes EQS is slightly shorter than the BMW i7, which measures 5.39 metres. And the BMW i7 is even heavier weighing 2715 kg compared to 2585 kg in the EQS 580 4Matic.
Could it be the conventional CLAR platform adapted for electric drive the main cause for the higher weight of BMW i7? Maybe. But at the same time, the BMW also has a higher payload of 535 kg compared to 475 kg on the EQS and can tow a 2000 kg trailer compared to 750 kg on the Mercedes. But the Mercedes has a bigger boot, 610 litres compared to the BMW’s 500 litres, and better access thanks to the generous tailgate. In the Mercedes, the boot volume can be extended to 1770 litres while in the BMW i7 the rear backrest cannot be folded down.
MBUX vs iDrive
As for the interior, we have a showdown between iDrive and MBUX. The Mercedes EQS is more avant-garde, and the 580 4Matic version comes standard with the sensational Hyperscreen with three screens hidden under a full-width gorilla glass window. In contrast, the i7 takes over the solution from the new iX with two screens smaller than the EQS hidden under a curved glass. But BMW makes a splash with its rear entertainment system with its 31.3-inch cinema screen with 8K resolution.
Mercedes promises that in the first half of 2022 it will offer Level 3 autonomous driving just like the S-Class under the name “Drive Pilot”. BMW also plans to do so but hasn’t announced an exact date.
The i7 xDrive60 and EQS 580 4Matic versions are not the most powerful models in the range. Mercedes has already introduced the AMG EQS 53 4Matic+ which develops 761 HP and 1020 Nm with the AMG Dynamic Plus package. It accelerates from 0 to 100 km/h in just 3.4 seconds and top speed is increased to 250 km/h. Price: 162,546 euros. And BMW promises an M70 xDrive version with over 600 HP and over 1000 Nm for which it promises acceleration from 0 to 100 km/h in under 4 seconds.
But let’s wait for the first tests.