Two manufacturers are pulling out of Formula E.
Honda's decision to pull out of F1 at the end of next year will leave just Ferrari, Mercedes and Renault on the grid.
But in Formula E, the all-electric series, there are currently six carmakers involved - Audi, Mercedes, Porsche, Jaguar, Nissan and BMW, as well as the famous American racing name Penske.
BMW and Audi, however, are pulling out - although Toto Wolff said in Bahrain on Friday that Mercedes is staying the course.
"It's certainly a little bit of a shake-up if two premium OEMs leave the series," he said.
"But they will have their reasons, which we must respect. I think the positive of the situation is that Formula E will make progress with learning - why are these two guys leaving, is there anything we can do?"
Wolff thinks a F1-style budget cap would be a good move for Formula E.
"Only if these little entities are profitable will they generate interest from shareholders, from people buying in, and it becomes a franchise value, like Formula 1 is going to be," he said.
"I see the future bright in terms of the setup of Formula E, but of course the series needs to deliver on all our expectations on branding, marketing and exposure."
