The Mazda3 brings together a long-term vision for sustainability and a desire to deliver an outstanding driving experience. Featuring best-in-class Skyactiv technology, Mazda engines combine the benefits of petrol and electric drives for superior performance and driving pleasure of unprecedented quality.
Mazda’s multi-solution approach to sustainability strategy means Mazda still works continually to improve the combustion efficiency and performance of its engines. At the same time, its engineers will integrate electric drive technologies, such as the mild hybrid system used by the Mazda3’s e-Skyactiv G engine and e-Skyactiv X engine.
Making its debut on the 2025 Mazda3, the 140ps 2.5-litre e-Skyactiv G engine replaces the outgoing 2.0-litre 122ps e-Skyactiv G engine. The popular 2.5-litre e-Skyactiv G’s use in the Mazda3 is part of Mazda’s ongoing commitment to meet customer and market requirements. This proven and advanced engine (that also sees use in the CX-5) features cylinder de-activation and the Mazda M-Hybrid mild-hybrid system.
Delivering a 18ps increase to the entry-point engine in the Mazda3 range, the real customer benefit is the increase in usable torque. The outgoing 2.0-litre e-Skyactiv G engine produced 213Nm at 4,000rpm, while the new engine produces 238Nm at 3,300rpm ensuring there’s a noticeable improvement in real-world performance. Plus, 0-62mph acceleration is 0.9secs second faster with the manual gearbox, while the Mazda3 auto is 1secs quicker. Other benefits include improved noise, vibration and harshness characteristics, which ensure enhanced refinement.
The introduction of the 2.5-litre e-Skyactiv G engine is another example of Mazda’s ‘right-sizing’ approach where increasing the engine capacity allows for a larger combustion chamber, meaning more space for an efficient and powerful combustion process. This allows for the lowest levels of emitted emissions at the same time ensuring the delivery of high levels of torque to improve driving feel.
The other engine in the Mazda3 range remains unchanged: Mazda’s unique Skyactiv-X SPCCI Spark Controlled Compression Ignition petrol engine - e-Skyactiv X, produces 186ps at 6,000rpm and maximum torque of 240Nm at 4,000rpm. The Spark Controlled Compression Ignition engine has a compression ratio of 15.0:1, while the optimisation of combustion control, modified pistons and the Mazda M Hybrid mild-hybrid system’s software results in a broad operating band of combustion efficiency, which ensure e-Skyactiv X not only delivers higher maximum engine torque but also improves real-world fuel economy. The intake valve timing and a modifying intake camshaft, lead to a reduction in pumping losses and further increase the engine’s specific heat ratio, helping the e-Skyactiv X’s excellent fuel consumption.
Mazda’s M Hybrid mild-hybrid system’s software delivers fast reactions on the system’s belt-driven ISGs torque control. This smooths drivability by increasing or reducing torque control when needed. For example, when the e-Skyactiv X’s air supply unit turns on – to provide sufficient air needed for a lean combustion fuel-air mixture - or off again, the units inertia creates torque fluctuations. The Mazda M Hybrid’s software enables torque reactions issued through the belt-driven ISG that are quick enough to flatten the torque curve. As a result, the engine feels smooth during linear acceleration.
Further adding to the efficiency of the Mazda3 across both engines, Mazda’s M Hybrid system is standard. A compact and highly efficient 24V mild hybrid set up, the system minimises fuel consumption and supports greater gains in fuel economy by recycling energy recovered during deceleration and powering an electric motor that assists the engine. A belt-driven integrated starter generator (ISG) converts the kinetic energy recovered during deceleration into electric power and stores it in a lithium-ion battery with a capacity of 600kJ. The system then uses a DC-DC converter to convert the power to the appropriate voltage and supplies it to the car’s electrical equipment. The lithium-ion battery is mounted between the wheels to minimise any effect on interior space while helping to optimise weight distribution and contributing to collision safety. In addition, the Mazda M Hybrid system supports extended engine off for increased fuel economy.
Even better, the Mazda M Hybrid system not only enhances the car’s environmental performance but also ensures better drivability. When the car is starting, accelerating or coming to a stop, transitions feel smooth and natural. By substituting engine torque for motor torque, the hybrid system can reach the same acceleration as petrol engines while using less fuel. Furthermore, engine speed is promptly adjusted during upshifts in order to enhance the driver’s subconscious clutch operation. Thus, the driver enjoys all the benefits of a mild hybrid without any sacrifices in terms of driving pleasure.
A world first, Mazda’s Spark Controlled Compression Ignition SPCCI Skyactiv-X engine technology made its debut in the Mazda3. Key to its operation is the use of a highly lean and emissions-efficient air to fuel mix, and the ability for the engine to switch seamlessly between conventional spark compression and combustion ignition, by using the spark plug to trigger both types of compression in different ways.
The e-Skyactiv X engine, like the previous version, is unique to Mazda: a series of injections first flood the combustion chamber with a lean mixture of fuel and air during the intake process, then a precisely injected richer zone of atomised fuel is added directly around the spark plug during compression. Because of the high 15:1 compression ratio, the first charge is close to spontaneously combusting anyway, and the injection of the richer mix creates an ignition in the local zone around the spark plug, which in turn increases pressure in the rest of the combustion chamber to the point where compression ignition occurs and the lean mixture ignites.
This SPCCI operation occurs during light load situations ensuring that the low fuel lean running condition improves economy and reduces emissions; however when the driver asks for more power the engine seamlessly switches to normal ‘stoichiometric’ fuel-air mixture of 14.7:1, while conventional combustion is only used under high engine loads and during very cold starts. The use of a spark plug to control compression ignition also avoids issues with knocking and unstable combustion.
The cleverness of Mazda’s SPCCI engineering is that the e-Skyactiv X engine operates in its most efficient mode for more than 80 per cent of the time, delivering improved fuel consumption, lower emissions and more torque than the larger capacity e-Skyactiv G engine. Combining some of the advantageous elements of both petrol and diesel engines, plus C02 emissions, e-Skyactiv X offers performance and environmental credentials in one package, while the new 2.5-litre e-Skyactiv G engine delivers improvements in drivability for the entry-point engine in the range.
Across the 2025 Mazda3 range the e-Skyactiv G and e-Skyactiv X engines can be matched to manual or automatic transmission. Automatic transmission is offered on Homura and Takumi e-Skyactiv G hatchback models, while automatic transmission is offered on Homura, Exclusive-Line and Takumi e-Skyactiv X hatchback models.
The stylish Mazda3 Saloon comes with a choice of automatic or manual transmission, but exclusively offered with the 186ps e-Skyactiv X engine and Exclusive-Line grade.