E-car's original electric vehicles are not new, and in the ten years of rapid development of new energy vehicles, consumers' anxiety about battery life has been running through the whole process. Today we will take a disk, why in the eyes of most people, the actual mileage of electric vehicles is false, often can not reach the manufacturer's promotional value, and we often see EPA, WLTP, NEDC and CLTC these endurance test which is more valuable to consumers.
Why do electric vehicles leave a bad impression of "false labels"?
To understand the false standard, first of all, we should actually talk about the fuel consumption of fuel vehicles. As long as friends who have bought a car will generally know the term fuel consumption of the Ministry of Industry and Information Technology. Somewhat similar to new energy vehicles, we often can't reach the fuel consumption of the Ministry of Industry and Information Technology of a car in actual use.
The fuel consumption of fuel vehicles is affected by many factors, but the actual fluctuations are actually not large - I believe that many riders can drive lower values than the Ministry of Industry and Information Technology when they are at high speed, and the inherent advantages of fuel vehicles in winter can also keep fuel consumption within a reasonable range.
In the era of new energy vehicles, these two scenes make the shortcomings of new energy vehicles completely exposed, high-speed endurance is 60% off, winter endurance is 50% off the phenomenon is not uncommon, coupled with the current charging scene is not perfect and charging facilities have randomness, owners must leave enough endurance to find charging piles, which also leads to electric vehicles in some cases experience is very poor.
Even if the existing mainstream new energy vehicle mileage has exceeded 600, 700km, and even some manufacturers shout out the slogan of 1000km, it cannot stop consumers' distrust of mileage.
In addition, the bad impression of electric vehicles leaving false labels is of course also related to the false publicity of some models of that year. At the beginning of the development of new energy vehicles, due to the lack of supervision and industry unified standards in the entire industry, the 60km/h constant speed cruising range used by some manufacturers was initially publicized.
If you take the analogy of a mobile phone, it is as if the mobile phone endurance test is closed to the network and the sound screen is the darkest for testing, without any reference significance - in the minds of consumers, this is false propaganda.
To sum up: the development of new energy vehicles originated from the policy, the first impression of the product born in such a context is not good, coupled with the attributes of the motor and the battery itself, its use characteristics are "anti-fuel vehicles", not used to + poor impression to leave a false "insult" for new energy vehicles.
Introduction of mainstream automotive energy consumption test standards
However, new energy vehicle companies that really want to do a big business do not want to be dragged down by infamy, so starting around the end of 2017, we found that many manufacturers defaulted to the use of NEDC endurance standards.
With the development of this market, more overseas new energy vehicles have entered the domestic sales, they have brought WLTC and EPA standards, of course, like the Ministry of Industry and Information Technology fuel consumption, we also need China's own endurance test standards, which is the CTLC standard launched last October.
After talking about the past impracticality, the next is the major energy consumption test standards that consumers are not clear, here is a brief introduction to each standard.
· NEDC (New European Driving Cycle): New European driving conditions.
Although the name says NEW, in fact, the NEDC testing process began to be developed in the 1980s, and the last standard update was in 1997 – 25 years now. Its testing process and working conditions have actually been very different from the existing situation, which is why it was later replaced.
The NEDA test standard mainly relies on 4 repeating urban driving cycles (UDC, known as ECE-15 in the urban driving cycle) and an out-of-town driving cycle (EUDC) to test, and uses wind to simulate wind resistance during driving, and the vehicle electrical appliances (such as air conditioners and headlights) in the experiment will be turned off.
Among them, the speed of the urban cycle is low, the maximum speed is 50km/h, the average speed is 18.77km/h, and the time of each cycle is 195s and the driving time is 1.013 km. The speed of the suburban cycle is higher, with a maximum speed of 120km/h, an average speed of 62.6km/h, and an effective driving time of 400s, for a total of 6.955km.
· WLTP (World Light Vehicle Test Procedure): World Light Vehicle Test Procedure. The new standard developed by Europe, named "World Standard", sounds quite reliable, "universal", in fact, it should be NEDC 2.0.
It can also be seen from the figure that the speed fluctuation and acceleration of WLTP are more drastic, and the test time will be longer than that of NEDC, and more importantly, for electric vehicles, the maximum test speed of the WLTP standard has reached 131km/h, and the driving distance has reached 23.25km, which is more testing for electric vehicles.
· CLTC (China Light Vehicle Test Cycle): Test conditions for light vehicles in China. Led by the China Automobile Research Center, it has traveled to more than 41 representative cities, established a collection fleet of 3832 vehicles, covering traditional passenger cars, light commercial vehicles and new energy vehicles, and collected about 32.78 million kilometers of vehicle movement characteristics, power characteristics and environmental characteristics data, and officially implemented in October 2021. The relevant standard is.
CLTC includes urban, suburban, high-speed three cases, removes the ultra-high-speed working conditions in WLTP, and the cycle time is the same as WLTP, which is 1800s. At the same time, CLTC-P (Chinese passenger car driving conditions, different tail label letters for different car types, such as the test standard for Chinese trucks is CLTC-LT) has an average speed of 28.96km/h and a maximum speed of 114km/h.
· EPA (Environmental Protection Agency): A test standard developed by the U.S. Environmental Protection Agency that has been implemented in the United States. It includes four tests: Urban Condition (The FTP-75 Proper), High Speed Condition (HWFET or HFET), Intense Driving Condition (SFTP US06), and Air Conditioning Conditioning Conditioning (SFTP SC03).
The average speed of urban working conditions is 34.12km/h, the average speed of high-speed working conditions is 77.7 km/h, the average speed of intense driving conditions is 77.9km/h, and the maximum speed reaches 129.2km/h. From the test update time, in order from new to old: CLTC>WLTP> EPA> NEDC.
● Who is more stringent in the four major tests?
For automobiles, the main factors that affect the performance of energy consumption are nothing more than road type, temperature, speed, wind resistance, weight, transmission efficiency and so on. For electric vehicles, due to the characteristics of the motor and the absence of the constraints of the gearbox, there are actually fewer factors that affect energy consumption.
According to the test mileage, average speed, test duration and other subdivisions, we compared several mainstream tests, which can be intuitively seen from the upper and lower tables. In terms of severity, EPA > WLTP> NEDC>CLTC.
Because the maximum speed is not enough, the average speed is not enough, so many electric vehicles from the original NEDC mileage to CLTC mileage, but the "book" mileage has become more, which I believe many consumers who pay attention to electric vehicles are clear.
We have to see which is more accurate, and actually we need to understand the logic and methods behind these test standards. After all, the global test standards are not necessarily in line with our general working conditions in China - whether it is the United States or Europe, in fact, the differences in automobile culture, region, and road design will also lead to obvious differences in the working conditions of the vehicles used by everyone.
We take the EPA as an example, the overall population density of the United States is lower than that of the mainland, the per capita driving mileage is longer, and there are not many traffic jams. So we look at the EPA test standards in fact, the average speed of the vehicle is higher, and the maximum speed of the high-speed working condition test has reached 129km/h, which is obviously not so in line with the domestic car conditions.
For the vast majority of people, our use of the scene is nothing more than the daily urban commuting and occasional high-speed driving, even if it is high-speed driving, because of the number of cars, we also need frequent acceleration and deceleration, the maximum speed is difficult to maintain for a long time 120km/h, which is our typical car conditions in China.
Let's take a look at the most used NEDC standard, as the old standard, nedc test problems now seem to be many: temperature constancy is obviously impractical, repeated urban circulation and high-speed conditions speed changes are very strange, the speed change is too "mechanical", most of the test process is uniform acceleration, uniform speed and uniform deceleration, plus your air conditioning is not open, obviously too far from our actual driving. This is also the reason why the European side needs to develop a new WLTP test standard.
CLTC standardS I am ready to interpret together with the WLTP standard, because as mentioned above, our country's CLTC standards in the formulation of part of the reference to the WLTP standard, also including urban, suburban, high-speed three situations, but deleted the ultra-high-speed conditions in the WLTP.
The overall average speed of the CLTC is lower, but in the context, it is more in line with the average situation in China - the CLTC standard is compiled by collecting data on the movement characteristics, dynamic characteristics and environmental characteristics of 32.78 million kilometers of vehicles in 41 representative cities. There are many vehicle traffic jams in our country, and even if they are on high speed, a considerable number of vehicles cannot reach the maximum speed of 120km/h, so it is reasonable that the average speed and maximum speed of the CLTC standard are inferior to WLTP.
In addition, whether it is EPA, or NEDC, WLTP, CLTC, they have never been aimed at electric vehicles, after all, there are still relatively few electric vehicles when NEDC has been used since the 1990s. Their ultimate goal is to test the energy consumption level of the vehicle, as well as the emission level - and eventually become a list that urges car companies to save energy and reduce emissions.
In general, the higher the average speed, the higher the energy consumption level, and the lower the range for electric vehicles. It is not difficult to understand why under the CLTC standard, the mileage of electric vehicles is more than in the NEDC era, because the average speed is lower - electric vehicles love low-speed scenes, don't they?
This figure is the acceleration comparison curve of WLTP, NEDC and CLTC, and the acceleration change of CLTC is the most dramatic, including more rapid acceleration and sharp braking. This also shows from the side that cling to the CLTC is indeed more in line with the driving scenario of our country's vehicles.
In the case of assuming a vehicle weight of 2 tons, the 100-kilometer drive energy of these three tests is shown in the table above , for fuel vehicles, the fuel consumption under CLTC conditions will increase by about 13.6% compared with the WLTP test, and the carbon oxide emissions will increase by nearly 55%.
If these tests are likened to exams, then these tests are obviously aimed at fuel vehicles, and the CLTC standard is a nightmare for fuel vehicles. Fuel vehicles without kinetic energy recovery will be more difficult under the CLTC standard than the MIIT Fuel Consumption Standard (WLTC) we used in the past. But with the help of kinetic energy recovery systems, electric vehicles can fully express themselves under the CLTC standard: so easy.
Therefore, electric vehicle owners should not say again: "The mileage is getting more and more virtual, what to do", because the CLTC standard is prepared for the vast majority of fuel vehicles in our country.
(On the left is the Tesla Model 3 US official website product page, the mileage is displayed as 267miles, about 429.7km, and the implementation is the EPA test standard)
So this part of my view is: for fuel owners, the future ministry of industry and information technology fuel consumption test standards after the replacement of CLTC standards, the ministry of industry and information technology fuel consumption will be more realistic, and electric vehicle owners, or EPA standards are the best to make.
What about electric cars without EPA range? Then the WLTC, what if there is no WLTC standard? Honestly, give it a 20% discount and it's done.
Because neither NEDC nor WTLC nor CLTC has a low temperature condition test, and the proportion of high-speed conditions has not increased, but only a change in average speed, so for electric vehicles, these three tests are essentially based on the discount problem of average speed - from the average speed of travel in the table, CLTC endurance will be about 29.5% higher than WLTP and about 14.8% higher than the NEDC standard.
Of course, if you want to compare the weight and configuration of each car, there may be slight differences, here you can look at the literature "NEDC switch to CLTC-P on the economy of pure electric vehicles[C]// Proceedings of the 2020 Annual Meeting of the Society of Automotive Engineers of China (2). 2020.[1] Zhao Qian, Xin Yu, Ma Yongzhi, et al.
What kind of tests are needed for electric vehicles?
From the above interpretation, in fact, we will find that clingtc testing for electric vehicles, the main test is the recovery level of electric vehicles, and other parts are still not examined.
So at the beginning of this part, I put forward a soul torture question: For electric vehicle owners, is it really the CLTC standard that is "claimed to be closer to China's driving conditions"?
From the point of view of everyone's complaints, everyone does not care about which car is more power-saving - our national electricity is only a few cents. People care more about how far my car can go in the worst-case scenario so that I don't have to call for roadside assistance.
From this point of view, should the state introduce a "nightmare" level test for pure electric vehicles? For example, ultra-low temperature, off kinetic energy recovery, constant speed test of 120km/h.
The answer is hard. First of all, the cost of ultra-low temperature or low temperature laboratory testing is too high - this requires a year-round open cold storage, basically only scientific research sites can provide, secondly, the existing ownership of electric vehicles is not high, don't look at the gimmick, by the end of 2021, the number of pure electric models is only 6.4 million, accounting for only 2.12% of China's motor vehicle ownership, electric vehicles are a "very small minority".
In addition, kinetic energy recovery is also one of the state-encouraged car company technology, the test closed kinetic energy recovery on the end of the inverted some - at this stage we do not how to start the kinetic energy recovery is still the driving habit switch is not adapted to and the driving experience when the start can be recycled, we may as well hope that the car company to optimize the driving experience when the start can be recycled.
In my opinion, on the one hand, the test standard is to give consumers a clear and clear reference to the real performance of the model they want to buy, and in turn, they can urge car companies to optimize in some aspects, such as: high-speed drive efficiency optimization, battery performance under low temperature conditions, the efficiency of the BMS system, including heat pump air conditioning, battery preheating system optimization, etc., which can greatly improve the endurance performance of the current new energy vehicles in the limit state, in order to make people feel at ease.
Full text summary: If you can add the "120km/h" constant speed endurance score at 0 °C on the basis of the current CLTC standard, then most electric vehicle owners will have a number in mind. As for friends in the -20 ° or even -30 ° areas, won't you, do you really want to buy a pure electric car?
Note: Some of the pictures and tables in this article are from the Internet