A Shift in Engine Strategy: Is Stellantis Moving from PureTech to FireFly?

One of the most debated engines in recent years has been the 1.2-liter PureTech developed under Stellantis. Widely used across brands like Peugeot, Citroën, Opel, and DS Automobiles, the engine gained notoriety not for performance, but for reliability concerns such as timing belt wear and excessive oil consumption.

Now, industry reports suggest that Stellantis may shift focus toward the GSE/FireFly engine family developed by Fiat.

Why FireFly Engines Stand Out

FireFly engines are not new—they’ve been used in multiple markets for years. However, their growing appeal lies in perceived reliability. Unlike the oil-bathed timing belt system in older PureTech engines, FireFly units use a chain-driven setup, which is generally considered more durable.

This shift could help Stellantis rebuild customer confidence while aligning with long-term engineering goals.

Focus on 1.3L and 1.5L Variants

The most promising candidates are the 1.3L and 1.5L FireFly engines. The 1.3L turbo variant, widely used in Brazil, can produce up to 185 hp and 270 Nm of torque, making it a strong all-rounder.

In Europe, the 1.5L version—seen in models like the Alfa Romeo Tonale—offers around 175 hp. This engine could be further optimized with hybrid systems to meet upcoming emission standards.

Hybrid Systems Lead the Transition

Stellantis is not just replacing engines—it is redefining its powertrain strategy. The introduction of eDCT, an electrified dual-clutch transmission, allows vehicles to operate more efficiently by integrating electric assistance at low speeds.

This hybrid approach could make FireFly engines a key component of Stellantis’ transition toward cleaner mobility.

Euro 7 and Strategic Uncertainty

Stricter Euro 7 regulations are pushing automakers to rethink their engine lineups. While FireFly appears to be a strong candidate, Stellantis has not officially confirmed the complete discontinuation of PureTech engines.

For now, the shift remains a well-supported possibility rather than a confirmed strategy.

What It Means for the Industry

If realized, this transition could mark a significant shift within Stellantis. Moving from French-developed PureTech engines to Italian-designed FireFly units would signal a broader transformation in the company’s engineering priorities and future direction.