With no restrictions on testing in the DTM, top teams usually hold private tests at all rounds on the calendar, with the exception of Norisring, incurring significant expenditure in order to do so.
It contributes to a third of their annual budgets, and means competing in the DTM costs significantly more than other GT3 championships of similar scale.
Due to high costs, many people in the paddock have called for a ban on testing in the DTM, including former motorsport chief Norbert Haug.
So far, the ADAC has remained sceptical about the prospect of imposing restrictions on private testing as GT3 cars are used in a variety of series around the world, making it hard to monitor any illegal running.
But SRO has shown that it is possible to put limitations on in-season testing in GT3 championships, and DTM could do well to follow in its footsteps and impose a ban of its own.
“There is definitely less testing [in GT World Challenge],” Plentz, who moved from the ADAC GT Masters to GTWCE in 2023, told Autosport's sister title Motorsport-Total.com. "We didn't have a single day of testing during the year at tracks where we raced."
In GTWCE, teams are free to conduct as much testing as they want until eight days before the start of the season. However, after that point, teams can only hold tests on tracks that are not on the calendar (or, as the season goes on, on circuits they have already raced on). The only exception to this rule are official SRO tests, such as the one before the Spa 24 Hours.
Source: Autosport