Lei Jun has triggered another controversy.
On May 18, Lei Jun drove live Xiaomi SU7 (Configuration |Inquiry) From Shanghai to Hangzhou. During the live broadcast, Lei Jun said that at present, Xiaomi's test team is still testing and will run 150000 to 200000 kilometers (single car), so that it can run its entire life cycle. No other car factory has invested in such large-scale testing before, and the total test mileage (total test mileage) may reach 11 million.
In this short speech, there are many "highlights". For the three questions, netizens raised more questions.
First, why is it that the Xiaomi SU7 has started to be delivered, but it is still being tested? Is it the semi-finished product that the user has received for "internal testing"? Second, the Xiaomi SU7 test vehicle completed the full life cycle test after running 150000 to 200000 kilometers. Is the life cycle too short? Thirdly, Xiaomi claims to be the largest test in China. What scale does it refer to?
The first two questions are actually not complicated. Whether the heroes in front of the keyboard recognize it or not, from the perspective of vehicle engineering, even if the vehicle has been delivered, the vehicle enterprises will continue to test the vehicle, which is a common practice in the industry. In fact, many car companies have found new problems through continuous testing. Therefore, just because Xiaomi SU7 is still testing after its launch and delivery does not mean that this car is a "semi-finished product".
On May 20, Xiaomi Automobile also replied to the "full life cycle" test. Lei Jun said that the test referred to the national public road test conducted by Xiaomi SU7 with 100 test vehicles in addition to the standard test vehicles. These vehicles are produced according to the mass production standard, and they will continue to be tested after the standard test is completed, and some vehicles will be tested to 150000 to 200000 km. The purpose is mainly for the subsequent OTA upgrade.
However, Xiaomi's so-called "largest" test needs to draw a question mark.
The largest test, the direction deviated
First of all, we need to make clear what scale Xiaomi refers to when it comes to the largest test of domestic car factories.
According to the total road test mileage of SU7 released by Xiaomi on March 28 this year, the test mileage of SU7 at the time of release was only 5.4 million kilometers, compared with, Boundary M7 (Configuration |Inquiry) It has experienced 7.5 million kilometers of testing before being launched.
Therefore, Xiaomi means the size of the team rather than the mileage. Previously, Lei Jun said that there were 576 test vehicles in Xiaomi SU7. This scale has indeed reached the level of some international car companies testing global models.
However, in terms of mileage, Xiaomi is far behind. cash BMW 5 Series (Configuration |Inquiry) Globally, more than 500 test vehicles have passed the test, and the total global test mileage has exceeded 10 million kilometers. On average, BMW's test mileage can reach about 20000 km per vehicle, while Xiaomi SU7 is less than 10000 km.
In this view, from the perspective of testing vehicle durability, it is not a good thing that the Xiaomi SU7 team is huge but the test mileage has not reached "far ahead".
But from a fair and objective point of view, the test mileage may not directly reflect the vehicle quality.
A new car needs a lot of road tests before it is officially delivered. In theory, longer test mileage can really find more problems. But this kind of test is never about the longer the mileage, the better, but the more comprehensive and efficient the better.
The new car test will cover all users' scenarios as far as possible, including extreme driving conditions. For example, every winter, in Yakeshi, Heihe and other extremely cold regions, a large number of new cars that have not yet been launched are being tested in winter; In summer, these new cars will run to Turpan and other places for high-temperature test. The purpose of these tests is to test the possible problems of the vehicle under various working conditions.
In addition, car companies usually test in different environmental areas such as high altitude, high temperature and high humidity to cover all scenarios that users may encounter. In order to improve the efficiency and comprehensiveness of the test, some automobile enterprises will further raise the temperature to 60 degrees or even 80 degrees or minus 40 degrees through laboratory tests, so as to further test the durability and reliability of automobiles in high temperature and cold environment.
For these tests, the final test mileage may not be very long. The main purpose of the car company is to restore the extreme use scenarios that users may encounter, and check whether the vehicle will encounter unexpected problems.
The durability test is not just about mileage. In order to improve the efficiency of testing, vehicle enterprises usually use rough roads to test vehicles. Taking the FAW-VW test field as an example, the endurance strengthening test area covers 16 special road conditions, such as mud roads and salt water pools. Although the total length is only 2.4 km, the test effect can reach 14 times (that is, driving 1 km of the test section equals to 14 km of users' daily use).
Such figures are not fabricated by car companies, but have scientific calculation standards. For example, SAIC Volkswagen has established a set of road load models based on the 240000 km road information of China. Specifically, this information is the road spectrum load spectrum obtained by collecting the acceleration, speed, displacement and other signals of the vehicle when driving, and analyzing them. The road spectrum load spectrum information of 240000 kilometers of roads in the country can enable vehicle enterprises to understand the driving conditions of vehicles under various road conditions, so as to predict the durability and performance of vehicles under different road conditions.
In other words, every new car does not need to run a lap on the 240000 km road, and there are more efficient ways. The load per kilometer on the SVP durability enhanced road of SAIC Volkswagen test ground is equivalent to the load of 39 kilometers of user roads nationwide, and it is up to 49 kilometers if compared with areas with good road conditions in East China and North China. It is equivalent to that each vehicle has tested one kilometer on such a road, which is equivalent to running more than thirty or forty kilometers on an ordinary road.
In addition, there are many durability tests that do not require a car to run. For example, the cyclic salt spray test for the corrosion resistance of metal parts has been started at the part stage. The durability test of the power battery does not require the vehicle to actually run on the road.
It can be seen that the length of the test mileage may not necessarily indicate the quality of a vehicle, and even the test mileage given by various vehicle enterprises may not be calculated under the unified standard.
However, when Xiaomi was questioned, he was not wronged at all. After all, Lei Jun was the first one to raise the topic. He brought out a parameter that was not meaningful, but he did not take the lead. This was a stone in his own foot.
Is the largest fleet size for testing or for publicity?
BMW and other international car companies have a large scale of testing mainly because their products are sold worldwide, so they need to carry out separate testing in many countries. But for Xiaomi, it is doubtful how valuable such a large team size is to the test itself.
In addition, as mentioned above, from the perspective of efficiency, it is not necessary for new cars to really travel all over the country. Instead, they can simulate the actual vehicle environment in different cities across the country through the national road data model and extreme driving test.
However, Xiaomi SU7 went to more than 300 cities across the country for testing. It is hard not to doubt whether it is for testing or for publicity?
If it is for testing, Xiaomi's testing method is not very advanced; If it is for publicity, don't call it the "largest" test team.
