Financial results of car manufacturers around the world in the first half (H1) of this year amid the COVID-19 crisis revealed "hidden weaknesses" of the producers, said a study by the German Center for Automotive Research (CAR) published on Monday.

The most profitable car brand analyzed was Porsche. With almost 10,000 euros (11,850 U.S. dollars) earned per car, the Volkswagen's sport car manufacturer was followed by U.S. company Tesla with 2,890 euros per car and General Motors in third place with 780 euros.

For every car sold, however, the Volkswagen group lost 415 euros.

Meanwhile, Toyota made a profit of 533 euros per car while French automobile manufacturer PSA-Opel made a profit of 707 euros per car in the first half of the year, according to the study.

Although Toyota recorded losses in the car business in the second quarter, reasonable sales in the first quarter in Japan, the United States and Europe gave it a "profit that was sufficient to offset the loss in the second quarter," the study noted.

The numbers showed that Volkswagen "certainly has to make greater adjustments than Toyota," said Ferdinand Dudenhoeffer, director of CAR.

A similar picture appeared when comparing Volkswagen with PSA-Opel. The upcoming fusion of PSA-Opel and Fiat Chrysler would further reduce Volkswagen's advantage with regards to economies of scale, according to the study.

At the same time, Volkswagen benefited significantly from its business in China. Volkswagen "must increase its speed of adjustment to the post-COVID-19 time," the CAR study noted.

Without Volkswagen's business in China, the loss per passenger car would have even reached 631 euros. Germany's largest car manufacturer was able to lower losses per car by 34 percent through its joint-ventures in China.

Business in China was "important for the profitability of German car manufacturers," stressed Dudenhoeffer. The close connections with China were "a stroke of luck for the German automotive industry."