Ford is so delighted with the burgeoning worldwide sales of its 60-year-old, petrol-powered Mustang that it is contemplating launching a new range of “authentic” combustion-engined variants that could include a four-door model for the first time in history.

Speaking exclusively to Autocar at the recent Goodwood Members’ Meeting – where he raced an Alan Mann-prepared Mustang V8 Notchback – Ford CEO Jim Farley claimed the Mustang is now “by far” the world’s best-selling coupé and has developed a huge body of followers worldwide.

However, he acknowledged that new derivatives would only be accepted by these supporters if they had the “performance and attitude” of existing models.

“We will never build a Mustang that isn’t a Mustang,” he insisted. “For instance, there will never be room for a small, two-row Ford SUV with a Mustang badge stuck on it. But could we do other Mustang body forms – a four-door or whatever? I believe we could, as long as these models have all the performance and attitude of the original.”

To begin this latest Mustang expansion phase, Farley believes Ford must start by adding lustre to the original coupé, investing both in models that are accessible to traditional buyers and in other versions that take the coupé further upmarket, the way that Porsche has done with its 911 GT3 RS and GT2 RS models. “Porsche has been smart about creating derivatives over the past 20 years,” he said.

“But we wouldn’t want to do things their way. We want to give them a good, American-style run for their money.”

One way of keeping costs down while increasing performance in the affordable version, he believes, may be to cut weight and a development programme is already under way to explore ways of achieving this.

Farley calls the recently announced, track-focused Mustang GTD – a Nürburgring-tested creation with 800bhp, a sophisticated aero package and a £240,000 price – “a down payment” on the performance Mustangs of the future. “We won’t stop with the GTD,” he said.

“At our best, we are an irreverent company. We need to keep doing derivatives that will surprise people.”

For all his expansionist plans, Farley believes Ford needs to be careful about diversifying the brand too far. He said: “Some people think we could mix Mustang with off-road driving – look at what Porsche has done with the 911 Dakar, and what Lamborghini has been doing. But I’m not so sure about that.”

One point of reassurance for Mustang stalwarts is Ford’s intention to continue building V8s “as long as God and the politicians let us”. Farley promises he will fight hard to keep these iconic engines and the manual gearboxes often linked to them in production.

He believes he can keep that promise even longer than specialist performance car makers – such as Aston Martin – because Ford is fast developing a supporting range of pure-EV models that will provide the fleet offsets needed to keep its ICE-powered siblings legal.

However, future Mustangs are likely to offer hybrid power, to reduce carbon emissions and to improve performance. Farley said: “We’ve been testing and we really do believe partial electric powertrains work well for performance drivers.”

“One thing I can promise, however, is that we will never make an all-electric Mustang,” added Farley, discounting the unrelated Mustang Mach-E electric SUV that shares its name.

“I look at other users of pure-electric power such as Formula E, and even companies like Rimac, and I just don’t think that would be right for Mustang. Great for other Fords – look at the worldwide success of Transit – but not for Mustang.”

Farley, who was appointed Ford CEO in late 2020 and has been rebuilding its model range ever since, sees the Mustang’s rise to global prominence as a big win for the firm.

He said: “When we decided, in around 2015, that Mustang should go global – with righthand drive and other expensive changes – it looked like we were taking a big risk. But it has paid off. Nowadays some of our biggest dealers are in countries like Sweden and Australia. I’d say Mustang’s future has never been brighter.”