Auto

Getting tighter in the back seat due to electric driving | Car

Passengers in the back seat pay the toll for electric driving. They are increasingly faced with less headroom due to a sharply sloping roofline. This also leads to smaller side windows and therefore less view. Designers opt for the sloping roofline to increase the driving range.

Especially the many electric SUV coupes that saw the light of day recently, painfully expose the problem. It was also established several times in the car tests of this site: in these cars you quickly sit in the back seat with your head against the roof. The reason is the sharply sloping roofline. The designers choose this to obey the laws of aerodynamics. Another consequence of the sloping roofline is that the rear side windows are getting smaller and smaller. They are often so small that passengers can barely see out.

In their pursuit of allowing cars to drive as many kilometers as possible on a single battery charge, car manufacturers cannot avoid having the roofline sloped. Not only with such an SUV coupe, in fact this is ideal for all electric cars. Extensive tests in advanced wind tunnels make it clear: only with a sharply sloping roofline, preferably all the way to the end of the car, will you achieve the least air resistance. If the wind is optimally guided along the body, the designer is rewarded with the largest range.

One of the best-selling SUV coupes at the moment: Volvo C40 Recharge. The coupé roofline results in less headroom compared to the XC40 from which it is derived. © Jan Kok | Boomerang Photography

,,Actually, you have to start descending with the roofline about the height of the front seats”, says Teddy Woll, development engineer and also head of aerodynamics at Mercedes-Benz. ,,So at the height of the rear passengers you must have already fallen considerably. As a result, people there have less headroom.” Designers sometimes try to circumvent this reduced headroom by making the sofa seat lower. But that in turn means that the passengers have to sit uncomfortably with their knees bent, with their thighs barely supported. Another solution is to install a panoramic glass roof, which allows the designers to avoid the headliner. Saves a bit of headroom. But such a glass roof makes cars more expensive and not everyone likes it.

Low, elongated and a sharply sloping roofline: the Dutch solar car Lightyear One is also ideally streamlined.
Low, elongated and a sharply sloping roofline: the Dutch solar car Lightyear One is also ideally streamlined. © Lightyear

The Dutch solar car also has the ideal roofline

Anyone who strives for the maximum range will end up with a flat and expansive model, such as the Dutch solar car Lightyear One, or the high-profile Mercedes-Benz EQXX, the prototype for a new Mercedes that will be launched on the market in two years’ time. This car has a driving range of more than 1000 kilometers. The so-called resistance coefficient (CW) is only 0.17 and that is a record. The development team of the Mercedes-Benz Formula 1 racing stable made an important contribution to the aerodynamic design. After all, even in Formula 1, they know that minimum air resistance leads to maximum performance.

“A compact, low car, stretched out as long as possible: that’s ideal,” says Teddy Woll. He foresees that car manufacturers will increasingly opt for this body shape in the coming years, at the expense of the currently so popular SUVs. ,,Because actually such an SUV is only inconvenient for this purpose”, says Woll. “A high car with a large front leads to too much air resistance.”

According to Woll, the SUV actually came at the wrong time: “You just don’t want such a high car when it comes to electric driving: far too much air resistance.” Nevertheless, many designers still opt for the SUV at the moment. , also for electric cars. This type is simply very popular with buyers. But car designers initially thought the SUV was also ideal for integrating the battery pack into it. After all, a higher floor is less noticeable.

But according to Teddy, that’s about to change. “More and more designers will find out that you can now also install a battery pack very flat. Just look at our EQXX. A flat package makes the shape of such a high SUV superfluous.”

Mercedes-Benz is setting a record with the extremely low air resistance of the EQXX. It travels more than 1000 kilometers on one battery charge. Here too it is clearly visible: low, stretched and with a sharply sloping roofline.
Mercedes-Benz is setting a record with the extremely low air resistance of the EQXX. It travels more than 1000 kilometers on one battery charge. Here too it is clearly visible: low, stretched and with a sharply sloping roofline. © Mercedes-Benz

‘The sedan is on the eve of a comeback’

In recent years, car manufacturers have mostly opted for SUVs, station wagons and hatchbacks as their body style. And all at the expense of the sedan, which fell into oblivion. Such a low car in which the trunk is shaped separately is classic and has been labeled more or less as old-fashioned and old-fashioned in recent years. But according to Teddy Woll, the sedan is now on the brink of a comeback.

“If we want an electric car to get as far as possible with its charged batteries, we can’t ignore the sedan. No other body shape offers so much gain when it comes to range. That ass, formed by the separate trunk, is also desperately needed. In addition, the length is very important. It is not without reason that our concept model EQXX is 4.90 meters long: quite a lot for a compact car. The longer the car, the better the streamline and thus the range on batteries. If we are going to apply that shape and length in, for example, the Mercedes A-class sedan, we will certainly succeed in achieving that thousand-kilometer range.”



Watch our automotive and mobility videos below:

Getting tighter in the back seat due to electric driving | Car
Source link Getting tighter in the back seat due to electric driving | Car

Back to top button