Why wouldn’t Ideal MEGA want this “magical technology” that both Tesla and Xpeng have praised?

In fact, its turning radius is smaller than that of the Model S.

Musk said with a smile while standing on the Cybertruck cargo box.

The full-size pickup truck under his feet is more than 5.6 meters long, with a wheelbase of more than 3.6 meters. When the rearview mirror is unfolded, its width is even more than 2.4 meters – more than 30 centimeters wider than the Ford F-150. , it can be said that it basically bids farewell to the Chinese market.

*my country's "Garage Building Design Code" stipulates that the width of a car parking space is 2.4 meters, and the narrowest parking space must not be less than 2.2 meters. Most domestic parking spaces use 2.4 meters as the standard.

But in the demonstration video at the delivery site, the Cybertruck showed flexibility beyond its size, and could maneuver through various obstacles with ease.

It is no secret that the Cybertruck has rear-wheel steering. A video of its U-turn was exposed as early as April this year, and Musk confirmed the existence of this configuration in July. Although the specific turning radius of the vehicle is currently unknown, judging from the video, the Cybertruck can complete a U-turn on a two-lane road in one go as long as it borrows a little more non-motorized lanes.

In this way, although it is difficult to park in China, it is not impossible to drive.

Rear-wheel steering is not just fancy.

The soil and water support the people, and so does the car. The Cybertruck itself is a great example.

The dispersed urban layout in the United States has created a strong demand for cars. Local residents need to frequently drive to and from companies, supermarkets and communities in their daily lives. Pickup trucks and full-size SUV models with stronger transportation and passenger capacity are naturally more popular. welcome.

Europe and Japan are characterized by high density and compactness. In cities represented by Paris, London, and Tokyo, the roads are winding and complicated, and parking spaces are tight. Short-wheelbase models with small size and sensitive control are naturally favored by people. .

In developed areas of our country, although the road conditions are better, the traffic environment is more complicated – on the left are the takeaway guys occupying the motorway and speeding past, on the right are pedestrians getting on and off the bus, and there are also a group of people who are blocked because of this. Motor vehicle, just thinking about this scene makes my blood pressure rise a lot.

But everyone knows the characteristics of the domestic market. Between "big" and "small", the latter is often the least popular one. This shows the importance of a large-space vehicle with rear-wheel steering to the Chinese market.

The first to sense the demand and put active rear-wheel steering technology into the market are still the "traditional giants" of Germany and Japan, such as Mercedes-Benz, BMW, Volkswagen, Honda, etc. If we ask about the more representative products in the past two years, Mercedes-Benz EQS has to be one.

All Mercedes-Benz EQS series are equipped with a 4.5° rear-wheel steering system as standard. If you are willing to pay an annual fee of 4,998 yuan to activate the 10° rear-wheel steering system, its minimum turning diameter can be shortened by nearly 2 meters to only 10.9 meters.

As domestic OEMs and supply chains continue to mature, rear-wheel active steering has gradually been brought into a relatively more mainstream price range by independent brands, such as Zhiji, Gaohe, etc., but it was the Xpeng X9 that really made waves. .

Who gave it the surname Xiaopeng?

Official data shows that due to the addition of rear-wheel steering, the Xpeng X9 with a length of 5293mm and a wheelbase of 3160mm has a minimum turning diameter of only 10.8 meters. Maybe you have no idea about 10.8 meters. You can use several popular models as a reference:

  • NIO ES6: 11.2 meters
  • Tesla Model 3: 11.6 meters
  • Xpeng P7i: 11.7 meters
  • Tesla Model Y: 12.1 meters
  • BYD Han: 12.3 meters
  • Ideal L9: 12.3 meters

It can be seen that whether it is compared with full-size SUVs, medium and large SUVs, or compact cars, Xpeng X9 has obvious advantages. Even compared with its own Xpeng P7i, it is even better.

Comparison of turning radius between Xpeng X9 and other models

When the Xpeng X9 made its debut at the 1024 Xpeng Technology Day, He Xiaopeng proudly stated that the X9 was "the world's first MPV model with rear-wheel steering" and even let the X9 slip around on the stage.

However, the X9's such flexible performance is not entirely due to rear-wheel steering. In order to leave more space for the cockpit, Xpeng limited the steering angle of the rear wheels to within 5°.

So how does Xpeng X9 achieve "four ounces of strength"?

An artist has his preferences

Even people who have never taken a driver's license should be able to understand this truth: at corners with different angles, the steering wheel is turned to different extents, that is, the front wheels deflect at different angles.

Then think about it conversely, if you increase the limit turning angle of the front wheels, can you also shorten the turning diameter of the vehicle? The answer is yes. On the front wheel of Xpeng X9, we can see a large turning angle design of 41.5°.

Generally speaking, medium and large MPV/SUV will set the maximum turning angle between 33-36°. For example, the maximum turning angle of Buick GL8 is 34° and the Audi Q7 is 36°. If the maximum steering angle is too large, it will directly cause the Ackermann angle (the difference in rotation angle between the inner and outer wheels) to increase, which will not only easily aggravate the side slip and wear of the tires, but also increase the pressure on the rack, star key and motor, and also increase the pressure on the rack, star key and motor. The centering performance of the suspension system and steering gear puts forward higher requirements. If Xiaopeng dares to put such a design on the car, it must have conducted in-depth tuning and coordination of the vehicle's sports performance engineering.

Car chassis design cannot be called an art, but it contains exquisite choices made by car company engineers in terms of performance, space, cost and other aspects. The biggest competitor of Xpeng X9, Ideal MEGA, took a different path under the same circumstances.

Although the car is over 5.3 meters long and has a wheelbase of 3.3 meters, Ideal does not allow MEGA to use rear-wheel steering. Many people believe that this is a trade-off made to ensure cabin space. And this statement is not entirely correct.

As a company that has long focused on gross profit margins, Li Auto is highly sensitive to costs. Therefore, faced with the trade-off between space requirements and performance, its most likely choice is to appropriately sacrifice part of the performance to achieve the cost target and meet the optimization requirements for internal space. The use of smaller 18-inch wheels in all Ideal MEGA series is a good example, ensuring lateral space for the third row of seats.

If Ideal is willing to spend money, it can also improve the steering performance of the vehicle without sacrificing internal space. It’s not hard to say – bigger tire envelope.

Tire envelope refers to the space where the tire does not have physical contact with the body and chassis parts when the vehicle is at the steering limit. This space will be restricted by many factors, such as wheel alignment parameters, suspension system design, body structure, etc. . In short, tire envelope is a key indicator of the vehicle's handling performance and is also a consideration for matching the steering and body.

There are generally two methods to exchange for a larger tire envelope while maintaining the same cabin space. The first is to customize narrower tires like the BMW i3 in the past, bringing a larger steering angle. But the ideal MEGA is not a small car like the i3 after all, and it is not practical to use tires that are too narrow.

The second method is similar to the common wide-body operation of performance modification. If the ideal MEGA can expand the wheel eyebrows like the Xpeng X9, it can also make enough space for rear wheel steering.

But it should be noted that Li Auto's choice to control costs is not something worthy of criticism. Obtaining a healthier gross profit, or using the budget elsewhere, are both reasonable choices. Again, chassis design involves the comprehensive considerations and trade-offs of car company engineers in terms of performance, space, cost and other aspects.

Maybe, this is really an art.

Anyone with wheels is interested and welcome to communicate. Email: [email protected]

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