Stellantis STLA One platform revealed as basis for 110 new cars from Citroen, Peugeot, Fiat, Vauxhall and the rest

It’s hard to keep up with the multitude of different platforms available in the armoury of giant car maker Stellantis, but the new STLA One promises to be its most important yet. 

Announced during Stellantis Investor Day 2026, the STLA One architecture will be put into use for the first time next year, before growing into a “mega platform supporting 30-plus models and targeting more than two million units by 2035,” according to the maker.

The parent firm of Fiat, Citroen, Vauxhall, Peugeot, Maserati and Alfa Romeo also revealed that STLA One is designed to cover B, C and D segments – essentially catering for everything from a Vauxhall Corsa to Peugeot 5008. 

The modular architecture isn’t just able to underpin a variety of segments, but will be multi-energy too. Ned Curic, Stellantis’ Chief Engineering and Technology Officer, said: “STLA One is a clear example of a truly modular strategy, giving us the flexibility of a multi-energy platform without carrying inefficiencies from one propulsion system to another.”

By wrapping up several fuel types into one platform and thus minimising complexity on production lines, Stellantis also says it’s targeting a 20 per cent improvement in cost while also upping component recycling and reuse by up to 70 per cent.

Some technological features of STLA One were also announced. Having brought in Chinese brand Leapmotor a few years ago, Stellantis says STLA One can utilise ‘cell-to-body’ integration of the battery, improving rigidity while reducing costs, weight and complexity. This technology is already in use with the Chinese firm’s C10 and B10 EVs. 

Elsewhere, STLA One will also use Stellantis’ new ‘STLA Brain’ – a central computer and software architecture, which could work in a similar fashion to BMW’s Neue Klasse ‘Heart of Joy’. 

There's also steer-by-wire technology and STLA ‘Smartcockpit’ which Stellantis claims will “define a new way for customers to interact with their vehicles”, plus STLA “AutoDrive”, which will be an autonomous driving system, though the levels of autonomy for this haven’t been announced. 

The STLA One announcement comes alongside Stellantis’ £52 billion ‘FaSTLAne 2030’ strategy which will see 60 new vehicle launches and 50 “significant refreshes” between now and the end of the decade.

Did you know you can sell your car through Auto Express? We’ll help you get a great price and find a great deal on a new car, too.