How to choose an inline six-cylinder and plug-in mix？ The new Mazda CX-70, domestic 2.5L is good

With the official voice for the CX-70, Mazda’s "mid-to-high-end SUV" product line puzzle is nearing completion. In addition to the sturdy body that can solve Mazda’s space problems, it is comparable to the design and texture of first-tier luxury brands. The 3.3T inline six-cylinder turbocharged engine can be said to have played with the nerves of "horse fans" many times. However, the next point of view is not sour grapes. From a technical point of view, Mazda’s turbocharged engine may not have its naturally aspirated engine, which is suitable for the domestic market.

Mazda with T, in order to do better self-priming?

Technology is always in the same vein. Judging from the specifications of the Mazda 2.5L naturally aspirated engine, we can push the perspective to the era of EFI 10 years ago. At that time, the Mazda 2.5L engine codenamed L5, which is an updated version of the classic 2.3L power, has already brought the black technology of variable intake manifold. By adapting different lengths of intake manifolds at high and low speeds, the output power at low speeds can be adjusted, and the intake air volume at high speeds can be adjusted. The vehicle can obtain a wider torque output range, creating a supercharger-like effect. As for the 89mm cylinder bore and 100mm stroke, it was inherited by the subsequent famous Chuangchi Blue Sky engine.

Aluminium cylinder block, alloy cylinder liner, and new connecting rods, crankshafts, aluminium pistons and other components make the Chuangchi Blue Sky engine lighter and more powerful than the previous L5 series. Of course, the most important changes to the new engine are the application of high-pressure direct injection technology, which helps the engine "burn more fully", and the matching 4-2-1 exhaust manifold, which helps the engine "breathe more smoothly". Ultimately, this naturally aspirated engine, which can achieve a maximum of 14 compression ratios (13 compression ratios in China), achieves an excellent balance between fuel economy and performance.

But balance also means that it is not "extreme" enough. For this 2.5L Tron Blue Sky engine, an unavoidable problem is that it is difficult to adapt to larger models. Or, it is difficult to provide a more aggressive driving experience on relatively large models. To be more precise, the power output of naturally aspirated engines in low-speed scenarios is naturally disadvantaged. Blind increase of displacement does not have a universal operating basis. Then the remaining answer is turbo, or mechanical supercharging, or even superposition of the two. The superimposed solution is of course not suitable for Mazda’s product positioning. The input-output ratio of mechanical supercharging is also low, and it is contrary to the technical characteristics of Tron Blue Sky. Turbocharging is the logical option, but don’t forget that Mazda is looking for ways to help the vehicle follow better in low-revving scenarios. So Mazda uses turbocharging and doesn’t care about the so-called performance reserve at all.

According to the parameters of overseas models, on the basis of using high-quality fuel, the Mazda 2.5T engine can achieve a maximum power of about 186kW and a maximum torque of about 420N · m. From the parameters alone, this performance is almost caught up by the BMW B48 2.0T. But technically, Mazda simulated the operation effect of a variable-section turbine through a dynamic turbocharging system. The specially designed exhaust gas channel and butterfly valve allow the exhaust gas to quickly pass through the narrow channel at low speed, minimizing turbine hysteresis. On this basis, Mazda also did not forget to add a cooling exhaust gas recirculation system to push the compression ratio of the turbocharged engine to a high level of 10.5. Although it is not comparable to the naturally aspirated version, it was already quite exaggerated at that time. This also allows Mazda’s 2.5T engine to achieve acceptable fuel consumption under high loads.

Is Mazda’s plug-in hybrid more suitable for the Chinese market than a turbine?

In simple terms, whether naturally aspirated or turbocharged, Mazda’s mass-produced engines (non-rotators) in the ordinary civilian segment mainly provide a more foot-to-foot (the so-called human-horse integration) driving experience for daily working conditions, giving more daily driving pleasure that can be experienced. But under high-intensity working conditions, more emphasis is placed on the economic attributes of maintaining the power system, and it is clear that it is still an "ordinary civilian car". On this basis, if we look back at the 3.3T inline six-cylinder turbocharged engine, we will find that the theoretical basis of Mazda has not changed. Its high-power version can provide a maximum of 340 horsepower and a maximum torque of 500N · m under the use of high-quality fuel. Obviously, from the data point of view, it is not as good as the 3.0T straight six engine codenamed BMW B58B30P. But this is still not important, the focus is on what you want, not the parameters.

But as I said earlier, the turbo is Mazda’s medicine to solve the low-speed power output of its large-size models. At present, this batch of SUV products positioned as standard B-class and even C-class, if you bypass the turbo, what else can you do? Combined with the changes in the Chinese market, the answer, of course, is "live". The vertical platform provided Mazda with a stage for making big news, so the inline six-cylinder turbo was born. But this stage is also suitable for the 2.5L naturally aspirated engine, because it leaves enough room for the intervention of the P2 motor. And the characteristics of the motor under low-speed conditions directly obliterate the original intention of Mazda to make a turbo. From the perspective of parameters, the maximum power of Mazda’s 2.5L plug-in hybrid power reaches 323 horsepower and the maximum torque is 500N · m, which is basically on the same level as its own 3.3T high-power version.

Of course, there is no denying the advantages such as the smoothness and power texture of the inline-six. But from the perspective of most daily working conditions in China, the performance of Mazda’s 2.5L plug-in hybrid and its own 3.3T straight-six will at least be much smaller than the price difference after their potential landing. To take the simplest example, in a market where the vast majority of riders do not actively use high-grade gasoline (the impact of fuel labels on some Mazda engines has been repeatedly mentioned earlier). The large-scale promotion of more complex and expensive solutions (inline-six cylinders) is far less than a simpler and more affordable set (especially with relatively small batteries), and the plug-in hybrid power that is more in line with regional needs is more grounded.

Looking back, Mazda is by no means a car company that does not understand the mystery. Whether it is the localization of the compression ratio of the Chuangchi blue sky engine, or the caution of the 2.5T and earlier 2.3T turbocharged engines, it is the same. Looking to the future, facing the mid-to-high-end SUV product matrix from the CX-60 to the CX-90. After all, they are based on a new vertical platform and use high mechanical hardware such as 8AT. Just kidding, even if it is 2.5L naturally aspirated with a set of ISG’s 48V light hybrid system, as long as the price is right, the temptation is enough. What’s more, with the plug-in hybrid system, this is probably the most suitable answer for the current domestic car market. As for the six-cylinder in the dream, if it could be imported in small quantities, or even landed in the form of CKD, it could be regarded as satisfying the emotional needs of domestic "horse fans".