Dr Helmut Marko said the car rule changes for 2019 are "pointless".
For next year, car modifications including different front wings are designed to make overtaking easier.
But Marko, the top Red Bull official, is not impressed.
"It’s a pointless regulation change that costs us around 15 million euros," he told Auto Motor und Sport.
"As far as the downforce is concerned, we are already more or less back at the current levels. And it will have no effect on the overtaking problem.
"I think when we’re making decisions like that, we don’t need to talk about the budget cap," Marko added.
Nonetheless, Marko is hopeful the switch to Honda will put Red Bull in a title-winning position next year, as the Japanese engine "already has more power than Renault".