The New Porsche 911 Carrera GTS: A Powerful Performance Hybrid Engine
Porsche has introduced a new performance hybrid powertrain for the 2025 992.2 911 Carrera GTS, naming it the “T-Hybrid.” The focus of this configuration is on performance rather than fuel economy, representing a complete overhaul of the 911 engine that debuted in the 2017 model year. The T in T-Hybrid stands for Turbo, emphasizing its performance capabilities.
The engine in the 992.2 GTS is a 9A3B6 engine that displaces 3.6 liters, an increase from the previous 3.0-liter engine. It features a single electrically enhanced turbocharger and is supplemented by a powerful electric motor-generator. Both the turbocharger and the electric motor operate on a 400-volt electrical system.
The new engine design not only increases in displacement but also takes up less space. By shrinking from top to bottom, it creates room for the hybrid system’s power-control electronics. The intake manifold and cylinder heads have also been redesigned to be less bulky. The valvetrain now utilizes finger followers with less friction, eliminating the need for the previous variable valve lift system.
Despite the increase in displacement and higher boost pressure, the power output of the new engine only increases by 5 horsepower to 478, with peak torque remaining unchanged at 420 pound-feet. The reason for this is Lambda 1, which refers to a perfectly balanced ratio of fuel and air. Modern engines typically operate at Lambda 1 to reduce smog pollutants. However, this requirement limits the engine’s ability to use a rich mixture during boosted operation, resulting in reduced power due to ignition timing adjustments.
The T-Hybrid features a single electric turbocharger, as opposed to the twin turbos in the previous model. This electric turbocharger significantly reduces turbo lag at low rpm, achieving full boost in less than one second. It is larger than the previous twin turbos and has no wastegate. At high rpm, the motor turns into a generator, producing up to 15 horsepower to prevent the turbo from exceeding its redline.
To accommodate the larger electric turbocharger, Porsche engineers positioned it on the engine’s right side and used a crossover manifold from the left bank of cylinders to feed exhaust gas to the turbo. The engine’s muffler was tucked into the space on the left side, maximizing available volume. With no accessory drive cluttering up the back of the engine, the turbo’s exhaust is routed through a large pipe that contains the catalyst and particle filter.
The accessories on the engine have been simplified, eliminating the need for a starter or generator. The transmission-mounted electric motor performs both functions, providing instant startup. A compact motor drives the air-conditioning compressor, and the water pump has been moved inside the engine and driven by an extension of the oil pumps. This eliminates the need for any external belt to drive accessories.
The final power-producing element is the motor-generator fitted to the eight-speed PDK gearbox. It provides additional torque at low revs, mitigating any lag in pressure buildup from the electric turbocharger. The combined output of the engine and motor-generator results in 532 horsepower and 449 pound-feet of torque.
The T-Hybrid is equipped with a lithium-ion battery consisting of 216 individual cells wired in series and parallel. It has a maximum gross energy capacity of 1.9 kilowatt-hours and weighs about 60 pounds. The battery is constantly adding and withdrawing energy due to the hybrid nature of the vehicle, ensuring long battery life. It has its own liquid cooling system to maintain optimal temperature.
In conclusion, Porsche’s T-Hybrid engine represents a significant advancement in performance hybrid powertrains. Despite complying with regulations for Lambda 1, the engine delivers impressive power and torque. The single electric turbocharger reduces turbo lag, and the simplified accessory drive system improves efficiency. With its innovative design and technological features, the T-Hybrid engine sets a new standard for performance hybrid engines in the automotive industry.
