There are many reasons why domestically produced cars use Japanese engines.
First of all, Japan's machinery manufacturing capabilities are well-known in the world, so it is normal for Japanese engines to be exported. The second is that our domestically produced cars all started late. They do not have their own technology in the core of the engine, and they have always been unable to catch up with others. Major manufacturers such as Volkswagen, BMW, and Mercedes have their own technology and production capabilities, so they You can completely use your own engines without importing them. Domestic cars are just the opposite.
There is actually a big difference between domestically produced cars and joint ventures. It is true that joint ventures use domestically produced parts for domestic assembly, but joint ventures are only responsible for assembly, and the real design is still the work of the original factory.
Extended information:
At present, joint venture manufacturers generally have their own brands, which are the domestically produced cars we are discussing today. The joint venture vehicles of the joint venture factory are basically designed according to the standards, and every part basically corresponds to the corresponding experiment for verification. If it fails the experimental verification, it will be considered an unqualified part, and it is necessary to find a new raw material supplier to provide parts that meet the requirements. The above is ideal state.
Foreign brands have changed in China. Due to cost reduction or the strength of domestic joint venture partners, some product verification sometimes compromises conditions due to cost pressures, etc. For example, verifying the light resistance of a plastic part, the original standard It is required to be in the experimental state for 1000 hours. As a result, the sample part fails after 800 hours. If it is to be improved, the manufacturing cost of changing the sample will be doubled or even several times increased. Under the situation of cost pressure, the main engine manufacturer may think that 800 hours is acceptable. This The case was dismissed.
This is just an analogy. I guess you have heard many times that materials used in joint-venture vehicles are lowered and reduced due to the pursuit of profits. It is indeed a common situation. To sum up, relatively speaking, the design and development of joint venture vehicles still basically follow the original standards.