Four-cylinder engines are usually associated with efficiency and compact packaging, yet a handful of engineers have stretched the format to astonishing sizes. The five engines below represent some of the largest-displacement 4-cylinders ever fitted to production cars, ranked by their quoted capacities and framed by how they shaped expectations for what a four-pot could do in luxury, performance, and everyday driving.
1. The 4.2-Liter Panhard et Levassor X19 Engine
The 4.2-liter Panhard et Levassor X19 engine is widely cited as an early benchmark for the largest displacement ever achieved in a production 4-cylinder. Period data and modern retrospectives agree that this unit displaced 4,211 cc, a figure that still looks extreme for a four-cylinder layout and that places it at the top of ranked lists of the largest-displacement 4-cylinder engines. Built in the early 20th century, it powered high-end Panhard et Levassor sedans from 1904 to 1908, when the brand was competing directly with the most prestigious European marques. The X19’s long-stroke design, huge bore, and relatively low compression ratio reflected the fuel quality and metallurgy of its era, yet the engine still delivered reliable output that allowed heavy luxury bodies to cruise at then-impressive speeds.
What makes the X19 so significant is not just its size but the way it framed the four-cylinder as a viable choice for top-tier cars rather than only for modest runabouts. In a period when multi-cylinder engines were expensive and complex, Panhard et Levassor used this 4,211 cc unit to offer torque-rich performance with fewer moving parts, which simplified maintenance for wealthy owners who still expected dependable touring capability. The engine’s presence in large sedans also set a precedent that later manufacturers would revisit when they pushed four-cylinder capacities for racing and endurance applications. For historians and engineers, the X19 shows how early designers treated displacement as a primary tool for achieving smooth, flexible power, long before high compression, forced induction, or advanced valve timing became common.
2. The 3.8-Liter Mercedes-Benz M136-Based 4-Cylinder Special
The second entry in this ranking, a 3.8-liter Mercedes-Benz M136-based 4-cylinder special, illustrates how tuners and factory-backed projects stretched existing designs to reach some of the highest displacements ever seen in a gas-powered inline-four. While the standard M136 family was known as a modest postwar engine, specialist builds enlarged the bore and stroke to around 3,800 cc, creating one of the largest gasoline 4-cylinders documented in modern surveys of the highest displacement 4-cylinder gas engines. These enlarged units were not mainstream production items in the way a mass-market sedan engine would be, but they were installed in low-volume performance and endurance applications where sheer torque mattered more than refinement.
Because the base M136 architecture was originally designed for smaller capacities, stretching it to 3.8 liters required careful work on crankshaft balance, cooling, and fueling. Builders focused on maintaining reliability at sustained load, a priority that mirrored the concerns of contemporary endurance racing teams and long-distance rally programs. In practice, the 3.8-liter specials delivered a broad torque curve that suited heavy-bodied grand touring cars and experimental chassis, even if they never reached the production volumes of more conventional Mercedes engines. Their existence underscores a broader trend that enthusiasts still track today: engineers repeatedly return to the four-cylinder format, even in large-displacement form, when they want a relatively compact, serviceable package that can be tuned for specific performance goals without the complexity of additional cylinders.
3. The 3.5-Liter Duesenberg Experimental 4-Cylinder
The 3.5-liter Duesenberg experimental 4-cylinder represents a transitional step in American performance engineering, sitting between the company’s earlier racing fours and the larger straight-eights that later defined the brand. While the production Duesenberg Model A used a bigger engine, period projects and documented prototypes included a 3,500 cc four-cylinder that targeted both speed records and luxury touring, aligning it with the third-largest displacement tier in modern rankings of the largest displacement 4-cylinder designs. Engineers experimented with supercharger options on this 3.5-liter unit, using forced induction to extract more power from its already generous capacity, a strategy that foreshadowed later American and European performance trends.
From an engineering perspective, the Duesenberg experimental four showed how American designers were willing to pair large displacement with advanced features like overhead camshafts and pressure lubrication, technologies that were still far from universal in the early 1920s. The 3,500 cc capacity gave the engine a strong torque foundation, while supercharging allowed it to chase speed records and competitive racing results without sacrificing drivability in heavier luxury bodies. For stakeholders in the emerging performance market, this combination of displacement and technology demonstrated that American manufacturers could match European rivals not only in size but also in sophistication. Even though the better-known Duesenberg engines would later eclipse it in fame, the 3.5-liter experimental four remains a key reference point in discussions of how far engineers were willing to push the four-cylinder format in pursuit of both prestige and outright speed.
4. The 3.2-Liter Stutz Series 4A Engine
The 3.2-liter Stutz Series 4A engine, used in 1920s Stutz Bearcat sports cars, is another standout in the history of large-displacement four-cylinders. With a quoted capacity of 3,200 cc, it appears in modern surveys of the highest displacement four-cylinder car engines as a prime example of how early American manufacturers balanced size with sporting intent. The inline-four layout kept the engine relatively compact and light compared with contemporary sixes, yet it produced more than 90 hp, a figure that gave the Bearcat serious performance credentials on both road and track. Stutz engineers focused on robust construction and effective cooling, which helped the 4A earn a reputation for durability in competition and spirited road use.
In the broader context of this ranking, the 3.2-liter Stutz shows how displacement could be used strategically rather than simply maximized. By pairing a large four-cylinder with a lightweight chassis, Stutz created a car that felt agile yet powerful, a combination that appealed to early sports car buyers and privateer racers. The engine’s success in racing circles influenced later American performance thinking, where big-displacement fours occasionally resurfaced in sprint and dirt-track applications. For modern enthusiasts and collectors, the 4A’s blend of 3,200 cc capacity, over-90 hp output, and proven reliability illustrates why some of the largest four-cylinder engines were not just engineering curiosities but central to the identity of the cars they powered.
5. The 2.9-Liter BMW M12/7 Racing 4-Cylinder
The 2.9-liter BMW M12/7 racing 4-cylinder earns the fifth spot in this ranking by pairing substantial displacement with a legacy of competition success and technical innovation. While the BMW M20 family is better known as a six-cylinder, BMW’s four-cylinder M12/7, enlarged for certain applications to around 2,900 cc, stands out in modern discussions of the best four-cylinder engines because of its tunability and versatility. Developed from BMW’s robust M10 architecture, the M12/7 was adapted for touring car racing, hill climbs, and other series where regulations allowed relatively large-displacement fours. In naturally aspirated form, the 2.9-liter configuration delivered strong torque and a wide power band, making it suitable for both sprint events and endurance races.
What distinguishes the 2.9-liter M12/7 in the context of this list is how its displacement worked in concert with advanced engineering rather than acting alone. The engine used sophisticated cylinder head designs, high compression ratios, and carefully developed fuel and ignition systems, all of which allowed it to exploit its 2,900 cc capacity without sacrificing reliability. Its success helped cement BMW’s reputation for building four-cylinders that could compete at the highest levels of motorsport, a reputation that later turbocharged variants would amplify. Modern performance surveys that track the most powerful four-cylinder engines often point back to this lineage, while reliability-focused overviews of long-lived powerplants, such as those highlighting durable Hyundai engines, show how the same priorities of robust design and careful tuning continue to shape four-cylinder development across the industry.
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