In recent years, people have placed higher and higher demands on automobile performance, one of which is its hill-climbing ability. There are even off-road vehicle companies that have such a sign: the car we produce has a 100% gradeability!
Many people are confused, what does 100% slope mean? Can you climb any slope? Isn't this very unreasonable?
Netizen’s doubts
Before discussing this issue, we must first understand the difference between angle and slope.
The difference between angle and slope
Slope is an important indicator of a car's off-road ability. The greater the slope, the stronger the car's climbing ability.
Simply put, if we think of the slope as the hypotenuse of a triangle, then the slope is the ratio of the vertical height of the triangle to the horizontal distance, which is the value of b/a in the figure below . Slope is a number less than 1 and has no unit, so for convenience of expression in daily life we usually write it as a percentage. The angle is different. It refers to the angle between the slope and the horizontal line. The unit is degrees.
Slope and angle diagram
For example, if a car moves 200 meters horizontally and rises 100 meters vertically when going uphill, then its slope is 1/2 and the angle is 30 degrees. In this way, the problem mentioned at the beginning becomes clear. slope of 100% means that the horizontal distance and vertical height are equal, and the angle is exactly 45 degrees at this time. In other words, this car can climb up to a 45-degree slope. The so-called 100% is just an attractive gimmick.
After understanding the concepts of slope and angle, we can't help but ask: How much slope can a car climb at most? Are those nearly vertical climbing scenes in movies and television real?
In fact, it is impossible for any car to climb a slope exceeding 45°. Once this angle is exceeded, no matter how strong the adhesion is, there is no way to resist the force of gravity, and the car will inevitably roll over or slide downhill. Otherwise, it will violate the principles of mechanics, and even Newton will disagree. Most of the pictures you see in movies and TV shows give people the illusion of "vertical" because of the different shooting angles.
What affects the climbing ability of a car?
In this case, what factors affect the climbing ability of a car?
First of all, the most intuitive thing is the power of the car . On a horizontal surface, having a car with more power can accelerate in a shorter time, which looks very cool; while on a slope, strong power can ensure that the car climbs smoothly and does not roll over.
The power of a car is mainly affected by the engine torque, which is the size of the driving force during a single rotation of the engine. The greater the torque of the engine, the stronger the power of the car, and can move forward on a higher slope. So we must pay attention to this parameter when choosing a car.
In addition, The driving method also has a great impact on the power of the car. Four-wheel drive is better than two-wheel drive, You can think of a car climbing a hill as a person climbing a mountain. Four-wheel drive is equivalent to the person using both hands and feet, and he can naturally climb steeper slopes; Rear-wheel drive is better than front-wheel drive , this is because when driving on a slope, a front-wheel drive vehicle has poor grip because most of its weight is concentrated in the front, and it is easy to slip.
Secondly, cars are also affected by friction when climbing hills, so the grip of the tires and the material of the slope are also very important. Extremely powerful off-road vehicles will be equipped with tires with many patterns to increase friction.
The impact of the ramp material is even greater. No matter how powerful a car is, it cannot climb the slope on the glass.People who like adventure also know that when driving a car uphill on snow or riverbeds, its capabilities are always weaker than usual.
Finally, the approach angle of the car also has a great influence on the climbing ability . When a car is parked smoothly on the ground, the angle between the plane tangent to the outer edge of the front tire and the horizontal plane is its approach angle; correspondingly, the angle between the plane tangent to the outer edge of the rear tire and the horizontal plane is The angle between them is the departure angle of the car, as shown in the figure below.
approach angle
departure angle
So, how does the car's approach angle affect the car's climbing performance? For an off-road vehicle, the greater the approach angle, the higher the minimum ground clearance, and the stronger the passing ability. It can climb steeper slopes; and the departure angle mainly affects the car. Excellent downhill performance, if the departure angle of is large enough, the off-road vehicle can easily go down the slope without worrying about getting stuck.
Although an ordinary car does not have particularly high requirements for approach and departure angles, we do not always drive on the broad road and sometimes face mud and dangerous shoals, so we must choose a car with a large approach angle.
What is the climbing ability of common car models?
Having said so much, what is the climbing ability of common models in daily life? How to choose a car with better performance?
is first of all the most powerful off-road vehicle. Because most people drive off-road vehicles to explore and seek excitement, people attach great importance to its climbing performance. The most powerful off-road vehicle can climb up to 100%, which means it can rush up a 45-degree slope! Currently, the more famous Mercedes-Benz G-class , Land Rover Defender , etc. on the market can achieve this climbing rate.
In addition, the climbing degree of Toyota Land Cruiser can reach 83.9%, Nissan Patrol can reach 80.11%. The performance of these cars is quite good, and off-road enthusiasts can consider it.
Off-road vehicle
The ordinary cars we usually drive are relatively powerful and have very good climbing capabilities. Generally speaking, its climbing degree can reach about 32%, which is completely sufficient in daily life. Climbing a small slope is basically no problem.
The climbing ability of urban SUV is slightly weaker , because it is positioned as a car driving on flat urban roads, so there is no need to think too much about climbing. Therefore, its climbing degree is generally around 28% .
The climbing ability of new energy vehicles is the weakest. The maximum climbing degree of and is between 25% and 30%, so they cannot go to places where the road is too rough.
A certain new energy vehicle
Conclusion
Now that we know that it is impossible for a car to climb a slope exceeding 45 degrees, we must not fight against science. Don't think that your car is very powerful and can climb any slope. After all, if you really fail to climb it, you will lose more than just your car.
In addition, when buying a car in a 4S store, you should also be careful not to easily believe the "fooling" of the clerk. You should ask clearly whether they are advertising the grade or angle, so that you can make the correct judgment based on your own needs.
Reference:
[1] CNKI briefly discusses the relationship between road slope percentage and ramp angle "Motorcycle Technology" 2012.03.10
[2] Guangming.com What kind of car is good at climbing 2020.10.09
Author: Yu Wen Review: Xiaoyang proofreading editor: Li Zi
