Mazda drops downsized turbo for reliable 2.5 naturally aspirated engine

Mazda swaps the 2.0 for a 140 hp 2.5 NA engine, sparking industry debate

While half the industry has rushed to downsize engines—three cylinders, one liter, turbocharged and praying for reliability—Mazda has done the opposite: replacing its 2.0-liter blocks (122/150 hp) with a 2.5-liter naturally aspirated engine producing 140 hp and 238 Nm of torque. The announcement, reported by km77, peine a seemingly settled war: engine displacement as a proxy for durability. And no, this isn't nostalgic regression; it's a strategic pivot against emission regulations that strangle small engines.

The core message is clear: Mazda's gasoline engines are "slightly" more reliable than the downsized units from other brands, often mocked by enthusiasts. The provocation worked. Within hours, opinions split into three camps: those applauding the larger displacement, those confused by the power drop compared to the previous engine, and those suspecting pure cost accounting.

Why Mazda reduces output from 150 to 140 hp despite larger displacement

The most repeated question has a trick answer. The 2.5-liter block isn't new; it's a detuned update of the Skyactiv-G used in the Mazda 6 (190 hp). The brand limited its output to meet emission and fuel economy standards without resorting to tiny displacements, something a fourteen-year-old engine didn't have to endure. Thus, the 2.5 produces less than the 2.0: not a technical step back, but a regulatory concession.

The argument holds economic logic. Using a single gasoline block from the Mazda 3 to the CX-80 allows scale savings and range homogenization. Some call it strategy, others impoverishment: jumping from 2.0 to 2.5 to add just 18 hp, critics argue, only makes sense for cost reduction. Moreover, road tax based on displacement costs more than double that of a smaller engine.

Real-world consumption: 7.5 liters vs. catalog claims of 4

Here things get interesting. Official figures place the 2.5 above the 2.0 in all tests, but road experience tells a different story. A Homura trim owner, paying €29,000 upfront, claims to achieve under 5 liters per 100 km at 100-120 km/h in sixth gear, reaching 4.3 liters at 90 km/h on flat roads. Another user with a 140 hp 2.5 from fourteen years ago states it consumes the same as the new one: 7.5 liters per 100 km.

This data is disorienting. If an old engine consumes like a new one, what improved? The consensus is twofold: lower emissions and fewer components prone to failure. Little comfort for those watching gas bills. Defenders of naturally aspirated engines argue that small turbos shine at 100 km/h in homologation cycles but become thirsty above 120 km/h, requiring extra fuel to prevent knock due to high pressure.

Direct injection and dirty valves: the overlooked problem

One of the most technical points concerns carbon buildup. In indirect injection engines, injectors sit outside the chamber, and gasoline acts as a solvent, keeping intake valves clean. In direct injection engines, injectors are inside the chamber and wash nothing: valves accumulate grime from the crankcase ventilation system. This is the dirty side of modern efficiency, explaining why some veteran blocks age better.

Price: €27,900 and drivetrain uncertainty

The Mazda 3 starts with this engine at €27,900. The comparison is direct: a generalist car at €23,000 with a 1.0-liter 110 hp engine versus this 140 hp 2.5. The €5,000 difference, according to circulating calculations, pays off if consumption remains low and the engine lasts as promised. The lingering question is traction: some assume permanent all-wheel drive, while others ask directly if it's front-wheel drive. The conversation doesn't clarify this data.

The conclusion isn't final. With tightening regulations, road taxes penalizing displacement, and eco-labels hanging by a thread, Mazda's bet could be the last of its kind or the first move of a counter-revolution. How long until the rest copy what they called barbarism just two days ago?