Ross Brawn has said that he wants more car manufacturers to enter Formula 1.
This week, it was finally confirmed that the Ferrari-linked Fiat brand Alfa Romeo is entering the sport in 2018 as Sauber's title sponsor.
Yet F1 sporting boss Brawn told Sport Bild: "There are several premium manufacturers that I would like in Formula 1.
"Porsche is one of them, but also Aston Martin and Lamborghini. That's why we need to create an environment that's attractive to them."
Brawn said it is therefore crucial that F1 simplifies the engine rules for 2021.
"I guarantee you - with today's power unit, no manufacturer is interested in getting started. That's why we have to make it cheaper and easier," he insisted.
Alfa Romeo's involvement next year marks a return after 30 years away from the sport.
