A frequently debated topic among Porsche owners is whether the 4.0L naturally aspirated flat-six engine found in the 718 GTS 4.0, Spyder, and GT4 shares the same lineage as the GT3 engine. Some videos and discussions claim they are from the same family, and I occasionally receive questions about this myself. After thorough investigation, a clear answer has emerged.

To put it simply, the engines in the 718 GTS 4.0, Spyder, and GT4 are not from the same lineage as the GT3 engine. Rather, the 718’s 4.0L engine is a uniquely evolved power unit with a fascinating development story behind its technology.

What Engine Codes Reveal About the Truth

Understanding Porsche engines starts with their engine codes. The engine code for the 718 GTS 4.0, Spyder, and GT4 is 9A2 EVO. In contrast, the GT3 engine carries the code 9A1. This difference is not just a label—it signifies fundamentally different architectures.

Tracing the roots of the 9A2 EVO engine leads to the 3.0L turbocharged engine found in the 911 Carrera (992 generation). In other words, the 718’s 4.0L engine is a naturally aspirated power unit newly developed based on a turbocharged engine. Meanwhile, the GT3’s 9A1 engine is a purpose-built design carrying the DNA of a racing car. This divergence in lineage highlights the essential differences between the two engines.

Technical Differences and Similarities at a Glance

Looking at bore and stroke, both engines share the same dimensions: 102×81.5mm. Displacement is nearly identical as well, with the 718 at 3995cc and the GT3 at 3996cc. However, these surface-level similarities don’t mean they are the same engine.

The most striking difference is in the redline. The 718 GTS 4.0 revs up to 7,800rpm (8,000rpm for the Spyder and GT4), while the GT3 engine spins all the way to 9,000rpm. This gap isn’t just a tuning choice—it reflects fundamentally different internal design philosophies. Power output also differs: the 718 GTS 4.0 produces 400PS (420PS for Spyder and GT4), whereas the GT3 exceeds 500PS. Additionally, the 718 engines feature cylinder deactivation technology for improved fuel efficiency, which the GT3 lacks.

The Surprising Connection to the 992 Turbo Engine

Interestingly, the 718’s 4.0L engine shares a deep relationship with the 992-generation 911 turbo engine. Both belong to the same 9A2 EVO engine family and share core architectural elements. This is no coincidence but a result of Porsche’s modular engineering strategy.

Specifically, the engine block and crankcase structures are common. The 718’s naturally aspirated 4.0L engine can be described as a “naturally aspirated sibling” of the 992’s 3.0L turbo engine, essentially the turbocharger removed and displacement increased. This design allows Porsche to efficiently unify engine components across the lineup while optimizing each model’s unique characteristics.

The fact that these engines can be produced on the same assembly line further supports this connection. This approach reduces development costs, streamlines quality control, and boosts production efficiency—all while delivering the distinctive engine character that makes the 718 so special.

The Unique Appeal of the 718’s 4.0L Engine

Not being from the same lineage as the GT3 engine doesn’t diminish the value of the 718’s 4.0L powerplant. On the contrary, it boasts its own unique charm. Based on the 911 Carrera’s turbo engine but reborn as a naturally aspirated unit, it offers a smooth revving experience up to 7,800rpm, a robust 400hp output, and the linear throttle response that only a naturally aspirated engine can provide.

Combined with the mid-engine layout, these traits create the distinctive driving dynamics that define the 718. Whether cruising through city streets or attacking winding roads, this engine’s character shines. While it follows a different philosophy than the GT3, it is equally captivating.

Moreover, the inclusion of cylinder deactivation enhances fuel efficiency for everyday driving. Unlike the GT3, which is more of a track-focused machine, the 718’s engine balances daily usability with spirited performance. This blend of practicality and sportiness is the true value of the 718’s 4.0L engine.