For Renault, the figure was just 62 percent.
Schober evaluates about 250,000 questionnaires sent to private households twice a year. The surveys contain 160 questions to research consumer habits in nine areas.
They are related to current and planned consumer behavior, such as a vehicle purchase.
Brand loyalty for Toyota and Volkswagen was clearly higher in spring 2005 than it was in fall 2002, according to the surveys. But, it fell slightly for Audi, BMW and Mercedes customers.
About 6.4 percent of Opel drivers are considering a switch to VW, and VW is also now the first choice for 6.3 percent of Renault customers and 6.2 percent of Ford owners.
The BMW brand presents an option to 5.3 percent of Opel owners. The figure was 5.1 percent for current Ford owners. And 4.9 percent of the Peugeot drivers would now choose Bavaria over France.
Schober's data exhibit a fundamental trend in brand loyalty. But they can become a leading indicator for changes in loyalty, said Schober spokesman Marcus Mende, especially "if the data from consumer surveys can be linked with the registration figures from the KBA," the German federal transportation office.