2019 can be called the “Year of the Engine” for independent brands. Judging from the engines used in new car launches, Geely Automobile has entered a new generation of 1.8T and 1.5T era; Changan Automobile has entered the Blue Whale era; SAIC and GAC have also ushered in their respective new generation of 1.5T and 2.0T engine vehicles. There are also those who are taking a different approach, such as Dongfeng Fengshen. With the advantage of being backed by the Dongfeng Group, its Fengshen AX7 model is equipped with a 1.6T engine jointly developed by PSA and BMW, with a peak torque of 250N·m, and a 10-year warranty policy, which also makes it competitive. Greatly enhanced.
Why do these manufacturers focus on launching new engines in 2019? This is inevitably inseparable from the transition to National VI emission standards. Based on more stringent emission requirements, if the engine wants to reduce emissions without reducing performance, it means that more advanced technologies must be adopted. Whether it is the plan of "independent design and international suppliers" or Fengshen's plan of purchasing big-name engines from overseas brands relying on the advantages of Dongfeng Group, they have achieved "National VI, low fuel consumption and strong power". The centralized launch of their respective new generation engines has also greatly enhanced the product strength of self-owned brand models.
Then why is it said that the advanced technology installed in engines after achieving National VI, especially National VI B, has increased significantly? We might as well seek the answer through the public engine dismantling event held by Dongfeng Fengshen on December 26 to see what advanced technologies the engines entering the National VI B era have.
The 2020 Fengshen AX7 is equipped with the second-generation EP6? 1.6THP engine, which is based on BMW TVDI core technology. Specific technologies such as continuously variable valve lift (Valvetronic), exhaust Advanced technologies such as continuous variable gas timing (DVVT), twin-scroll single turbocharging structure (Twin scroll), chain drive timing system, new generation crankcase ventilation system, in-cylinder high-pressure direct injection, control the intake and exhaust efficiency, the atomized fuel injection is accurate and sufficient, achieving homogeneous combustion under all working conditions, the compression ratio has changed from the previous 9.2 to 10.3, the maximum power can reach 125kW, the maximum torque is 250N?m, on the other hand, it also contributes to the comprehensive operating condition fuel consumption of only is 7.0L/100km.
Among them, Valvetronic variable valve lift technology is BMW's core patented technology. It uses continuous variable valve lift, steplessly adjusts the valve opening and controls the time according to the position of the accelerator pedal, allowing engine load changes and cycle management. The demand is reduced to a minimum, thus increasing the power by 10~15%, reducing fuel consumption by 7%, while improving the smoothness of engine operation, reducing exhaust emissions, and achieving excellent engine response speed.
DVVT intake and exhaust continuously variable timing system uses intake and exhaust dual VVT technology to obtain a valve superposition angle that better matches the speed. The intake timing phase can provide a crankshaft angle of up to 70°. Variable angle, exhaust timing phase can provide a maximum crankshaft angle of 60° to make the intake and exhaust as full as possible, with higher gas distribution efficiency to obtain greater power, torque and emissions. performance.
Twin?Scroll dual-channel turbine technology effectively improves turbine efficiency. It directs the exhaust gases of cylinders 1 and 4 and cylinders 2 and 3 that do not interfere with each other in the exhaust stage to the turbine respectively, avoiding exhaust interference and reducing exhaust gas energy loss. , improve inflation efficiency. In fact, the twin-scroll design improves the turbine efficiency of 7-8 and provides 5 fuel utilization; at the same time, it significantly reduces the supercharging lag, and the turbo lag can be reduced by 1.5s; in addition, the two scrolls are used for simultaneous propulsion The rotation of the turbine effectively improves low-speed torque, and the lower turbine intervention speed can make the driver clearly feel that the power of the 2020 AX7 comes faster.
The timing system’s anti-tooth-jumping protection design prevents tooth-jumping and reduces the chance of failure. The new generation crankcase ventilation system adds a gas dilution pipe to the traditional supercharger dual-branch crankcase ventilation system to reduce the proportion of crankcase ventilation exhaust gas, improve the oil and gas separation effect, and reduce carbon deposits.
In addition, the engine adopts a lightweight design, while the application of high-strength, low-friction piston components and hollow wax-filled sodium valves improves reliability.
Unlike many manufacturers who excessively pursue high power and performance (squeezing the limits of the engine, resulting in reduced service life and high engine failure rate), Dongfeng Fengshen uses a balanced powertrain with low fuel consumption, high performance, lightweight and stability. to provide consumers with optimal power solutions.
In terms of transmission, this engine is matched with Aisin’s third-generation 6AT gearbox on Fengshen AX7. This latest version has smaller shifting impact and higher efficiency than the previous two generations of 6AT products.
I have previously tested the 2020 AX7 model equipped with this engine for about half a month. My impression is that since the AX7 is a large car, this engine presents more of a It is close to the power generation characteristics of a 2.4L self-priming engine.
From the data point of view, the peak torque of this engine starts to be released at 1750 rpm and decays after 4500 rpm. The peak torque intervenes early and has a wide platform. The actual driving experience is that the power output at medium and low speeds is smoother than expected, and the power increase at medium and high speeds is very powerful. This feels more like a self-aspirated medium-displacement engine with a linear and progressive output effect, rather than a common engine. It's the kind of small turbocharger that "feels like a push when you step on it" but has insufficient reserve in the middle and rear range.
In terms of fuel economy, the new engine has obvious advantages. The Ministry of Industry and Information Technology’s comprehensive fuel consumption of the 2020 AX7 is 7.0L, which is not only lower than the 7.5L of the 2020 Boyue RPO? 1.8T, but also lower than the 2020 model 7.2L of Boyue Pro? 1.5T model.
As for fuel consumption data, there is a certain gap between the actual measured value and the nominal value. According to my experience, the difference between Chinese brands is often larger than that of joint venture brands. In order to test the real fuel consumption, I cleared the mileage subtotal as soon as I got the car. After half a month of long testing, my cumulative result was 7.6L, with a sample mileage of 1,100 kilometers. Considering that I was driving the car in Chengdu, the provincial capital city, the test results were better than my expectations. After all, Fengshen AX7 is an SUV that is relatively half a class up in size.
In addition, in terms of chassis performance, thanks to the CR-V chassis genes and the settings of the front and rear four-wheel independent suspension, the "integrity" of the 2020 AX7 is very good, crushing the cement connections at the entrance of urban tunnels The thick feeling when wearing it is very high-end. The adjustment is mainly based on comfort. The suspension is very efficient in resolving vibrations. In addition, the tires are also set to comfort. The vibration transmitted to the steering wheel and buttocks has been greatly reduced. You can confidently drive relatively smoothly when driving on potholes and bad roads. quick.
Conclusion:
For consumers, it is naturally a good thing for manufacturers to take the opportunity of upgrading to "National VIB" to intensively invest in advanced engines. Especially in the compact SUV segment, the engine advantage is relatively obvious - new technology engines can generally achieve fuel consumption levels of 8 or 9L and good acceleration performance, while in the past, most independent compact SUVs were 11-13L. fuel consumption level.
It is expected that in 2020, independent brands will further introduce engines with new technical forms into a wide range of products, and those models without advanced engines will have an increasingly difficult time surviving.
Text｜Zhang Junling
Pictures｜Author and Internet
This article comes from the author of Autohome Chejiahao and does not represent the views and positions of Autohome.