Stronger doesn’t equal faster

Free travel for free citizens – this slogan has been used for decades to successfully argue against a speed limit on Germany’s autobahns. To this day, Germany is the only country in Europe with no general speed limit but only a recommended guideline speed. On 70 percent of Germany’s autobahns, drivers are allowed to drive at any speed. With so many roads having no speed limit, it’s only natural for people to drive fast. Therefore, it is not surprising that the engines of passenger cars on sale in Germany are becoming more powerful on average. And thus the top speed is also increasing – at least in theory. But is that true? And by how much has engine performance increased in the recent past?

JATO Dynamics has taken a look at how performance, acceleration and top speed have changed between 2020 and 2022. One thing is certain: The trend towards more drive power continues unabated. Between January 2020 and August 2021, newly registered cars had an average engine power of around 140 kW – with slight fluctuations up and down. From September 2021, engine power increased significantly, rising to 145 kW and then falling again to 140 kW the very next month. The monthly ups and downs then became a permanent trend. Although engine power fell to that of the beginning of 2020, in the long term, engine power increased. The biggest jump was registered between July 2022 (138 kW) and September 2022 (156 kW). Despite a brief decline, the two-year observation period ended with an average output of 156 kW – an increase of 13 percent after all. But why was this the case?

E-cars are often more powerful

In January 2020, the share of purely battery-electric passenger cars (BEVs) and plug-in hybrid vehicles (PHEVs) of all new registrations was less than five percent each. By the end of 2022, this had changed significantly: BEVs already accounted for more than 30 percent and plug-in hybrids for around 15 percent. Both drive variants often have high performance.

PHEVs in particular have an electric motor on board in addition to the combustion engine, which on average increases overall performance. “In the meantime, a clear trend can be identified,” says Eric Haase, Vice-Chairman and Managing Director of JATO Dynamics in Germany. “As the number of e-vehicles increases, so does the average drive power.”

But does that automatically lead to higher top speed? And what about the acceleration values? As a rule, more engine power allows vehicles to sprint from 0 to 100 km/h faster. But the sprint to highway speed depends not only on air resistance but also to a large extent on the weight of the vehicle. The heavier the vehicle, the slower it moves forward. Electric vehicles are usually much heavier than their combustion-engine counterparts due to their batteries, which often weigh 500 or 600 kilograms. In addition, the very popular SUVs weigh considerably more than most vehicles from other segments – especially if they are electrically powered.

It is therefore not surprising that the average acceleration values to 100 km/h from the beginning of 2020 to the end of 2022 remained at approximately the same level between 8.4 and 8.8 seconds despite the increasing engine power.

At most, the fluctuations between the individual months are noteworthy. This was not the case for the average top speed. But the trend here is all the clearer. Contrary to the expectation that more engine power also means more top speed, a clear decline was observed here. The average top speed in January 2020 was 213 kilometres per hour. Although there was always a month or two in between when the top speed rose again, it gradually declined over the 24-month observation period. At the end of 2022, it was “only” 195 km/h.

Speed limit conserves the battery

Here, too, the increasing number of electric vehicles is the cause. This is not due to the higher weight, but because the manufacturers are reducing the top speed. The first reason is technical because electric motors and batteries get hot very quickly under high loads. This is often observed in cell phones. If many functions are performed at the same time, the device quickly gets warm. At high temperatures, the called-up power must be reduced to protect the battery cells. So to ensure that a constant top speed is possible over a wide range of the battery’s state of charge, it can make sense to limit it to a certain value. “The discussions about speed limits probably won’t stop right away because of this”, Haase says. “The limits are simply not big enough for that.”

The second and more important reason is the range. High speed means high energy consumption. This is true for all types of drive, but with the currently still thin charging station network and charging times that take significantly longer than the usual refuelling stop, energy-efficient driving with an e-car is much more important than with a diesel or gasoline engine. Nevertheless, it is rather unlikely for the maximum top speed to increase again in the future as battery capacities rise and the charging station network becomes denser. After all, a lower Vmax ensures less wear and tear meaning that the vehicles require fewer large braking systems, for example. This reduces production and warranty costs. It can also be assumed that more affordable vehicles in the lower segments will come onto the market in the future, which will generally have a lower maximum speed.

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