Here's Why Porsche Is So Obsessed With The Boxer Engine

What is a boxer engine?

While most car manufacturers use the inline or V engine configurations, Porsche has decided to stick to a boxer layout for its sports cars. A boxer engine is also called horizontally opposed due to the two sets of pistons "pushing against each other” similar to how boxers exchange punches. They are also called flat, due to their physical characteristics and the 180-degree "V-angle". However, there is one key distinction between boxer engines and flat engines.

Why Does Porsche Use Boxer Engines For Its Sports Cars?

Porsche’s relationship with the Porsche engine spans more than 90 years. Despite Porsche being owned by VW Group, the German automaker is adamant that its sports cars will not share any hardware with the parent company’s more mainstream products. Porsche’s reason for continuing to use the boxer engine goes further and has a lot to do with improved driving dynamics due to the engine layout’s inherent benefits.

Better handling in harsh conditions

One of the most defining features of the Porsche 911 is the rear-mounted boxer engine. Even today, all 911s have the engine over the rear axle (in some older generations, it was even behind the rear axle). The logic behind this decision stems from practicality and safety reasons. Before all-wheel drive became widespread in light passenger cars, Porsche engineers figured that cars that had the engine in the rear performed better during winter.

Low center of gravity

The boxer engine’s flat design allows it to sit much lower in the engine bay compared to an inline or V-engine. This is also what allowed Porsche to retain the 911’s signature, sloped rear end without compromising on engine capacity or the overall packaging. The biggest benefit comes in the corners, where a lower center of gravity allows for a much better weight transfer.

Better stopping power?

One less-known advantage of having a rear-mounted, low-profile, boxer engine is that it aids rear braking. Most vehicles have the inclination to understeer during mid-corner braking, due to the front brakes doing most of the work. Having the engine in the rear allows for better rear braking making the car nimbler and more "chuckable”.

Insane acceleration

Nothing launches from a standstill quite like a Porsche 911. Naturally, this is thanks to having the engine in the rear. During launch, even more weight is "thrown” towards the rear wheels, pressing them to the ground. It is why models like the Porsche 911 Turbo S Lightweight can do the 0 to 60 mph sprint in a hypercar-like, 2.2 seconds.

The inherent smoothness of the boxer engine

The boxer engine is inherently smoother due to the horizontally opposed pistons canceling each other’s movements out. Because of this, Porsche boxer engines are incredibly smooth and produce very few vibrations. This is especially true for the six-cylinder boxer engines. This allows for a more consistent performance and less stress on the engine. Porsche’s philosophy for the boxer engine revolves around five pillars:

• Consistent, lightweight construction

• Low center of gravity

• Outstanding revving ability

• High specific output

• Sporty and suitable for everyday use

Boxer engines are the best candidates for air cooling

Porsche was the last carmaker to feature air-cooled engines in its sports cars. This changed in 1998, with the introduction of the Porsche 996. All 911s after the 993 generation feature water-cooled boxer engines. That said, companies like Singer that reimagine classic Porsche 911 models, still produce air-cooled variants. Due to the pistons being further apart compared to inline or V-engines, the boxer engines as better cooling.

Boxer engines have a few inherent downsides too

More complexity

Boxer engines are more complex than most other engine types. They require more parts to manufacture, especially compared to inline engines. The engine building process is longer, more complex, and more expensive.

The boxer engine is a tight squeeze

Boxer engines may have a low profile, but they are very wide. The cylinder heads are as far from each other as possible. This makes servicing the engine a bit harder compared to other configurations. Moreover, the Porsche 911 and 718 engine bays are not the most spacious, and sometimes even something as simple as changing the spark plugs may necessitate taking out the engine.

The boxer engine is not the same as a flat engine

While they look similar on the outside, boxer and flat engines have one key difference. The difference comes from the number of crank pins featured. They serve to transfer the up-down motion between the crankshaft and connecting rods. Boxer engines feature one crank pin per cylinder while flat engines feature one crank pin for every two, horizontally opposed cylinders, similar to most V-shaped engines. Flat engines are, sometimes, also called "flat-V engines".

Hans Mezger’s boxer engine

Joining Porsche straight out of Stuttgart University, in 1956, Hans Mezger quickly became synonymous with Porsche’s boxer engine. Essentially, he refined the boxer layout while reducing developmental and production costs. In 1965, Ferdinand Piëch put him in charge of Porsche’s Motorsport division, with the goal of developing a Le Mans-winning Porsche. He is responsible for some of the most iconic Porsche race cars ever made, including the 917K (which featured a V-12), 911 Carrera 2.7 RS, and many others.

His influence goes further back since he developed the original 911’s 130-horsepower, six-cylinder boxer engine. There are a few reasons why Porsche models featuring Mezger engines are particularly sought-after. This includes the last analog Porsche 911, which was not available in the US. The last Porsche 911 to feature a Mezger engine is also what many believe to be the ultimate 911.

The future of Porsche Boxer engines

Porsche may have recently debuted its second fully-electric model – the Macan EV – but a six-cylinder boxer engine will continue to serve in the iconic 911. In fact, Porsche continues to offer a wide range of boxer engines in various configurations and displacements. Porsche promises that it will keep its flagship sports car combustion-powered for as long as possible. Porsche adheres to the highest standards of quality and in its Zuffenhausen factory, over 350 professional workers work on the iconic boxer engine, which is mostly hand-crafted. The first hybrid Porsche 911 is a fact, and it seems the T-Hybrid powertrain is the next evolution of Porsche boxer engines.