Questions and Answers on Basic Car Knowledge 2

Questions and Answers on Basic Car Knowledge 2

31. TIptronic (hand / self-integrated transmission) can be upgraded without any oil collection?
The car's engine management system is very smart, even if it is high-end without oil collection, it will not cause a serious bumpy feeling, but the computer will think that you want to accelerate at full speed without shifting the throttle. Try to collect half of the oil, the shift effect will be smoother, and then gradually add oil according to actual needs.
32. What is a CVT transmission?
CVT is stepless speed change. As the name implies, it does not change gears at several fixed ratios like traditional manual or self-shift. It mainly depends on two variable diameter pulleys to change the gear ratio, but within a certain range, the gear ratio It can be changed gradually, so as to reduce the bumpiness of shifting gears.

33. Should the throttle be increased or the first speed increase should be reduced when the third ramp is used for a slight ramp?
This is a very complicated and interesting problem. If you drive a vehicle, the maximum torque of the engine used will appear at a very low speed, and if there is no wave gear ratio that is far apart, you should not turn down the low gear randomly. The design usually appears on commercial vehicles or some diesel engines. Lowering the speed of these cars by one gear will cause the engine speed to rise sharply, and the result will be farther away from the Power Band. Although the gear ratio is improved and the wheel output torque is a little larger, the fuel consumption will increase greatly. On the contrary, keeping the gear and speed at the peak torque point, adding a little oil will be enough to cope with the upward slope.
But for most private cars or sports cars that use gasoline engines, the maximum torque is above the middle and high speeds, and it feels weak at low and medium speeds. The effect of increasing the throttle is not large, because the gasoline engine Air Fuel RaTIo is limited , From low load 15: 1 to high load and high output 12: 1. Exceeding this ratio, whether it is too much or too little gasoline, will make the engine more weak. So when you feel tired and refuel, the trip computer senses that the engine needs to output more torque, it will increase the Air Fuel RaTIo a little thicker, and delay the ignition time a bit to cope with the load. In fact, it can be divided into three aspects to determine whether the gear should be shifted: First, if the increased torque is still insufficient to cope with the ramp, the engine speed will continue to fall, which must be shifted, otherwise it will die. Now.
Second, if the increased torque is sufficient to cope with the upward slope, the vehicle speed and engine speed will gradually increase, so the torque output will be further enhanced, and then the computer will restore the fuel supply and ignition time to a lower load level.
Third, if you step on the throttle, the increased torque of the engine still just resists the upward slope. At this time, you should consider turning down the low gear. Although the method of maintaining the gear will eventually be more fuel-efficient, it is not beneficial to the engine and caused Problems include rising water temperature, carbon deposits and even internal parts damage and so on.
34. How to do Double Declutching and Heel and Toe?
Because it is too professional and difficult to explain without a picture, it will not be explained in detail here.

35. Side slipping will affect the cornering speed. Why do rally drivers still do this?
The friction between the tire and the ground sliding sideways is dynamic friction, and the grip force must not be as good as the StaTIc Friction of the wheel True Roll. This is the right reason whether it is dry road, wet road or snow, but it is necessary to find the best on different roads. The ideal Grip is very difficult for rally racing. At the same time, if the speed is reduced to keep the wheels from slipping, it is more unfavorable for the rally car using the Turbo engine. In addition, in the steep mountain race, sweeping into the corner with the tail In case of accidents, it just hits the mountain, so this kind of tail-sweeping into the corner has become almost the standard way of entering the corner.

36. Why use Double Declutch technology?
The purpose of Double Declutch is to match the speed of the input and output shafts of the manual gearbox. The output shaft is directly connected to the main drive shaft and the wheels, and the input shaft is connected to the crankshaft via the clutch. If the clutch is stepped on and turned into neutral, the input shaft It will disengage from the driving of the engine and the gear of the output shaft and lose all the power to rotate, so when the low gear is turned, if the speed of the input shaft matches the output shaft, the clutch and a little oil must be released in neutral to let the engine The power increases the speed of the input shaft.
37. When driving a hand-wave car, if you want to get the best power output and achieve smooth results, what speed should you refuel?
To achieve a smooth and powerful shift, the principle is very simple, that is, try to adjust the speed of the two sides of the clutch (engine and gear) to the same, and then engage, and this connection should be crisp and fast engagement, without relying on "hang" clutch To achieve the purpose of smoothing. This principle is simple to say, but it takes a little effort to succeed. Here are some quick tips. First of all, you need to know the ratio of each band of your car. You can find it in the manual of the car you buy. In general, five-speed hand-wave cars, each gear is about 1.5 times different. , That is, if you turn down a gear, the engine speed will increase by about 50%. Conversely, if you turn up a gear, the speed should fall to about 70% of the original speed. This is assuming that the vehicle speed remains unchanged during the shift. The file is only a matter of seconds, and the speed should not drop sharply.
With this concept, you can try to adjust the rotation speed to the appropriate clutch before shifting. For example, the first gear is accelerated to two thousand rpm. When the second gear is turned, the clutch should be engaged at about two thousand rpm, but in fact it is turned on High-end does not need to deliberately refuel to adjust the speed, because when oil is collected and the clutch is shifted, the engine will not fall to idle speed immediately because of Throttle's own delay and the inertia of the flywheel. It takes two or three seconds to fall Idle speed, when you switch to high-end, if you have a good grasp, you can engage the clutch without refueling. At this time, the engine speed just drops to the ideal about two thousand rpm, so you can get a perfect shift. If the six front speed is opened, for example, the six front speed of the IS200, after the third gear is a very dense ratio, after shifting to maintain more than 85% of the original speed, you need to add a little oil to loosen the clutch, but pay attention to turn on The fuel range of high gear must be less than the throttle depth before shifting, because the speed must be lower, and there is no load in neutral, and the throttle response will be stronger.
As for downshifting from high gear to low gear, it is necessary to refuel. At present, the engine speed should be a little higher after the gear shift. As for how high it can be calculated using the method listed above. One very important thing is that the downshift is usually done when going up and down. The uphill problem is not big, but when you are downhill, you should pay attention not to step on the clutch with only your left foot and replenish the right foot. The car will slide forward without braking, which is very dangerous, so we should not replenish the oil when the vehicle is inclined, so can the momentary sensation of the clutch be loosened? There are methods, which is what we often say Heel & Toe
38. In order to make parking smooth, some people who turn on automatic waves will switch to neutral when they are about to stop. Others often do not use braking to decelerate, but only tow waves to slow down. Are these methods appropriate?
It is not right to stop by means of neutral taxiing. The reason is that if there is a sudden danger on the road, the driver cannot give the car power to drive away from the danger in time. The reason for entering neutral after parking is also here. In addition, the so-called drag wave to slow down is also inappropriate. One of the main principles of gear shifting is to match the speed of the car. The car naturally needs to reduce the gear when it slows down, so it should be braked to a certain speed before downshifting.
39. You can't just use D gear for Yunkai Automobile, but you shouldn't always use manual gear to switch gear. Which statement is right?
Driving an automatic wave on an ordinary flat road can indeed be dealt with by D wave, which is a comfortable, reliable and effective method, but under rough road conditions and sudden traffic changes, if the driver knows to actively control the gear, it will be smoother Let the vehicle drive. The problem is that we must understand the way of control, otherwise we will return the D wave to let it operate automatically.

Can 40.235 / 45R17 be replaced by 235 / 45R18?
The 235 / 45R17 was replaced by 235 / 45R18. The size is not correct because the diameter of the entire tire is one inch larger.
41. Can the original tire size be 195 / 60R15 be replaced by 215 / 45R16?
No, if the meter's mileage does not change, you should change to 215 / 55R16 or 225 / 50R16
42. How to change the original 14-inch rim to 15 or 16 inches without affecting the tachometer?
Assuming that the original tire is a 185 / 60R14 tire, if the diameter of the wheel is not changed, 195 / 55R15 or 185 / 55R15 can be selected; if the original tire is 195 / 60R14, 205 / 45R16 can be used.
43. How many kilometers do you need to change tires?
Generally speaking, the tires need to be replaced every two years or so. In addition to being replaced due to wear, the tire materials will also age with time. If a set of tires is used for more than three years, the materials may harden or even if the tread is intact. Cracked. In addition, the depth of the tread should also be measured regularly, and replacement should be considered if the remaining 2 mm.
44. How can the new tire get into its best condition faster?
In fact, it refers to entering the best state, commonly known as "open tire" in the industry, which means that the surface of the tire is ground off. This layer of material will be coated with a release agent and its grip is low. In general, As long as you walk on rough road for more than ten minutes, it can already be worn away.
45. What is the reason for changing the diameter of the large rim? Is it to increase the ground pavement?
The replacement of the large rim is not to increase the contact area between the tire and the ground, but it is hoped to replace the tire with a lower Aspect Ratio, that is, a thinner tire, to provide a more sensitive and accurate tire feel, but the disadvantage is to reduce comfort. To increase the ground contact area, wider tires should be used instead of thinner tires.
46. What are the bad effects of using A / T tires to walk the ordinary streets?
The design of A / T tires is different from ordinary street tires, mainly because of the deeper pits. There are many pattern blocks and strong colloidal stone resistance. If it is used in the street, in addition to the high road noise, the table grip will be slightly inferior, but the wear resistance will be higher than that of the street tire. Today's A / T has a relatively wide road surface adaptability, mainly for the purpose of adapting to the Sport Utility Vehicle, so some A / T tires have been improved to have good comfort and handling even on normal roads, off-road It also has good sand removal ability.
47. What is the rim Offset?
Offset refers to the distance between the center line of the longitudinal section of the tire and the plane where the wheel and axle are connected after the wheel is mounted on the tire. If the center line of the tire is outside the contact plane, we define it as a negative offset. Generally speaking, FR cars will use negative bias, while FF will use positive bias. Although the Offset definition of the wheel is from the center line of the tire to the connecting plane, for an independent car, it defines the distance between the center of the tire and the axle bearing. This distance and the load on the tire are multiplied to produce a torque . That is to say, 1 acceleration or braking, vehicle weight, etc. will multiply this Offset distance, and become a moment acting on the bearing. Changing the Offset will affect the load on the bearing. At the same time, it will change the intersection point of the center line of the steering pin (King Pin) and the center line of the tire in the original front wheel positioning design, which will directly lead to heavier steering, and More sensitive to road reaction. In fact, the purpose of changing Offset, whether it is changing wheels or adding Spacer, is to obtain this keen steering feeling, but pay attention to the bearing will increase the load, and the tire may also extend beyond the sand board and cause unnecessary trouble.
48. How to interpret the tire specifications?
Example: 175 / 70R14 84S: 175 is the width of the tire surface (mm); 70 is the flatness ratio (height / width * 100); R stands for the radiation layer; 14 is the inner diameter of the tire (equivalent to the diameter of the rim); 84 is the load capacity; S is the maximum speed that can withstand (S-180KM / H, H-210KM / H, V-210KM / H or more)
49. How to interpret the rim specifications?
Example: 8.5jjx17 (-5) 5-114.3; 8.5 is the width of the rim (inch); JJ is the shape of the flange (with K.JK.J and C); 17 is the diameter of the rim (inch); －5 is the offset (MM); 5 is the number of gong bolt holes; 114.3 is the diameter of the axis of the PCD gong bolt (MM).
50. How do you change the size of general tires? (See table below)
Standard size No need to change the rim Need to replace the rim 185 / 60R14 195 / 55R14 195 / 50R15
205 / 65R15 215 / 60R15 225 / 55R16
205 / 55R16 225 / 50R16 225 / 45ZR17
51. What are Camber and Caster angle?
Looking at the wheel from the front, the angle between the wheel and the vertical line is called the camber angle. If the upper end of the tire is inclined outward, the left and right wheels are V-shaped, which is called positive camber.The role is to reduce the steering time. The required force makes the twisting of the tire easier to turn. If the upper end of the tire is inclined inward, it is in a shape of [eight], which is the negative angle (Negative Camber), which can help the racing car or some high-performance cars resist the centrifugal force when turning, but adjust Improper school will weaken the grip of the road.
Castor angle (Castor) refers to the front-to-back tilt angle of the steering shaft. Sex.
52. What is Kickdown?
The design of the automatic wave is to adjust the gear according to the load of the engine and the depth of the throttle.When the driver deeply steps on the throttle, it means that the engine is not strong enough or the driver wants to accelerate.At this time, the automatic wave will automatically turn down one or two gears to assist Acceleration. Drivers use this feature to deepen the throttle whenever they want to accelerate to shift the gearbox.This action is called Kickdown.
53. What is magic bile?
The so-called magic bile, the official name is Toyota Super Strut, Strut is the pillar type, which is the McPherson style (a type of car suspension name), Toyota Super Strut is improved from the McPherson suspension, with two under the pillar The rocker arm controls the rotation axis of the wheel steering, and a stabilizer bar is added to reduce the change in inclination.
54. What are Toe in and Toe out?
From a bird's eye perspective, the front wheel is in the shape of a toe in (Toe in), which is often used on rear-drive vehicles to counteract the camber tendency of the wheels. Conversely, the shape of the outside is in a toe out. To counteract the inclination tendency of the wheels, some front-wheel drive vehicles will be applied.Overall, the setting of Toe in or out is mainly to keep the wheels balanced while walking to offset wear.
55. What do FF.FR.RR and MR mean?
FF is a front-engine front-wheel drive car; FR is a front-engine rear-wheel drive; RR is a rear-engine rear-wheel drive; MR is a mid-engine rear-wheel drive.
56. What is Oversteering and Understeering?
The Chinese translation of Oversteering is called too much steering, commonly known as tail-flicking. This term is used to describe the actual steering angle of the vehicle in the bend is greater than the angle of the steering wheel, and the rear tires have excessively slipped.
Understeering can be interpreted as understeering or commonly known as head shaking, which is to describe that the actual steering angle of the vehicle in the corner is smaller than the angle of the steering wheel, and the front tires have excessively slipped.
57. What does GT mean?
The correct interpretation of GT should be Grand Touring or Grand Tourer. It represents some high-performance and luxurious and comfortable sports cars. But now GT has been generally referred to as a high-performance sports car, and there is no distinction between luxury and non-luxury.
58. What is Final Driver Ratio?
One of the main functions of Final Driver is to greatly reduce the speed of the drive shaft to meet the speed of driving on the road, that is, to reduce the transmission speed of up to thousands of revolutions per minute to a road speed of only hundreds of revolutions per minute For example, if the Final Driver Ratio is 4.0, it means that the drive shaft rotates four times before the wheel can turn once.

59. Is it okay to change the lower body without reducing the driving comfort?
If you want to lower the body a little, and you do n’t want to reduce the comfort, it will be a little contradictory, because the suspension stroke is limited, otherwise the wheels will hit the body. And lowering the body means that the stroke of the spring is shortened, and the spring still has to register in this stroke The compression deformation provides enough power to cope with the unevenness of the road surface. The only way is to strengthen the Spring Rate. Otherwise, even if you find a spring with a short length and the same Spring Rate, the wheel will hit the sand board or the spring will run out and produce a strong impact. The best choice is some springs with Variable Spring Rate design, which can provide a more comfortable effect in the initial stroke. As for the shock absorber, the spring should also be replaced with a matching shock absorber, because the ideal Damping The Ratio was originally calculated by Spring Rate and car re-enactment. It is simply inappropriate to change the spring instead of Damper; As for Coil Over Suspension Kits, usually the original ones sold on the market are harder and have a lower riding comfort. .
60. What is the function of Tower Bar? Why is it round or flat?
The function of the Tower Bar is to support the top position of the front suspension pillars, reduce the distortion of the frame, and allow the suspension system to work at the originally designed angle to avoid a sudden drop in grip due to the angle change.
The round ones are usually made of steel pipes, the flat ones are usually made of aluminum, the steel pipes are cheaper but heavier, and the aluminum ones are more expensive and lighter.
61. Is it possible to replace high-performance brake pads for general RVs?
High-performance brake pads are actually not suitable for daily driving. Its biggest advantage is that it has better high-temperature resistance, but the disadvantage is that the braking force is usually exerted at higher temperatures, and it is possible to scratch the original brake disc. And the replacement of low-performance cars with high-performance brake pads is of little significance for enhancing brake performance. If you have to change them, it is best to replace the disc and the leather together.
62. How often should the brake fluid be changed? What happens if it is not changed?
The brake fluid itself is a very stable pressure oil. Chemicals and high temperature are not easy to deteriorate it, but it has a characteristic that it absorbs moisture in the air, and the brake hydraulic system must allow the brake fluid to pass in the atmosphere. Normal operation, over time, the brake fluid may absorb water and turn into bubbles at high temperatures. When bubbles appear in the brake oil circuit, the brake performance will decrease. Therefore, the brake fluid should be replaced on time, maintenance and repair in the owner's manual In the column, there will be suggestions to change the mileage of brake fluid.Generally speaking, it is enough to replace it every 20,000 kilometers.In fact, this is only a small process.Some of the larger gas stations also have brake fluid replacement services.
63. How do I know that the brake pads have worn out?
The easiest way is to observe the liquid level of the brake pot.If it drops to the Minimum Level, it means that the brake pads are seriously insufficient.At the same time, the original brake pads of many cars will have warning copper pads attached.After the brake pads wear, the copper pads will contact The brake disc will make a sound, and the owner will notice it.Of course, the best way is to ask a professional technician to remove the brake pad for you to check.
64. What is a limited slip differential?
The limited-slip differential is installed in the middle of the drive shaft.In addition to the traditional differential that allows the left and right wheels to run at different speeds, it can also lock the left and right axles when one of the drive wheels loses ground grip. Opportunity to skid.
65. What kind of system is TCS?
TCS is the abbreviation of Traction Control System.The main function is to stabilize the tire when it is about to slip, to avoid runaway. TCS has a variety of different designs.The simplest is to control the electronic throttle to automatically collect oil, and the more complicated is to automatically drag. Use brakes to control wheel slippage, and even cut off the output of the engine.
66. How is the code on the oil label interpreted?
The specification and approval of the engine oil can be known from the API specifications. The so-called API is the abbreviation of the American Petroleum Institute. It integrates the protection of the engine oil to the engine. Anti-oxidation. Anti-precipitation and other importance, and makes an evaluation standard for the engine oil. The performance level used on the engine will be marked with the letter "S", the second letter is its performance level, for example, SJ is the highest grade, SA is the lowest. In addition, the engine oil used on diesel engines is marked with "C" "The word is used as the code, and the performance rating is CF as the highest level.
The oil stain is generally represented by two numbers, such as 10W / 60, W stands for WINTER (winter), indicating its fluidity at low temperatures and the ability to help the engine start, the lower the value, the lower the stain , The easier it is to start in a cold climate. On the other hand, 60 refers to the high temperature resistance and protection of the engine oil at high temperatures. The larger the value, the higher the dip and the more the engine can be protected at high temperatures. According to physical rules 10W / 60 seems to be a bit contradictory, how can the lower wettability at low temperature? In fact, the meaning of this compound wettability is that the oil can meet the wettability within these two extreme requirements, both low temperature and 10W fluidity, At high temperatures, there is still a degree of 60.
67. Is the octane number of gasoline the higher the better?
The appropriate gasoline octane number is to ensure that gasoline will not pre-burn in the middle of the compression stroke.If the engine design only needs 97 OCTANE, even if it is given 98 OCTANE, the meaning is actually not significant. The gasoline is compressed in the same state and then given Sparks ignite.
68. Many people say that Japanese cars need to change oil more frequently than European cars. Is this true? Why?
For many new European cars recently, the oil change time recommended by the manufacturer is indeed longer than before. In fact, Japanese cars are also moving in this direction, but the pace is not as good as European cars. The oil change period recommended by the car manufacturer has been extended, representing the maintenance of the owner. The cost reduction is naturally an improvement. In fact, it can be practiced in various ways to extend the oil change period. Let us think about it in reverse, why do we need to change the oil regularly? Because the oil will deteriorate after a period of use and will be lost There are several reasons for the effect of lubrication, such as being decomposed by carbohydrates, acidified by the combination of nitric oxide and sulfur, mixed with water vapor to form fouling, etc., which are all the problems that have troubled the engine lubrication system. The root cause behind these problems can be solved, and the service life of the oil can be extended. In fact, today's engine technology is indeed much improved than before. For example, carbohydrates, nitrogen oxides, etc. are due to the low air-fuel ratio or poor mixing during combustion. As a result, today's electronic fuel injection system has been very accurate, coupled with an improved ignition system to minimize the combustion of HC.NOX, combustion chamber with improved grinding technology It also reduces the flow of gas into the oil tank, and the strict control of the sulfur content in gasoline.This series of engine technologies basically embarked on embracing, which has extended the life of the oil.I believe that with the achievements of European cars, other countries ’ Depots will all go in the same direction.
69. What is Damper?
Damper, also known as Shock Absorber, is called a shock absorber or shock absorber in Chinese.It is a device in the suspension system that uses hydraulic pressure to absorb the shock of the road surface and is responsible for stabilizing the body.
70. How can the fuel consumption be improved most effectively?
We have already said that the fuel consumption is not necessarily proportional to the engine volume. The most important thing is the load. It is to be overcome by burning gasoline. The weight of the car, the wide tires, the four-wheel drive device and the driving habits all cause the engine. Load. So if you want to improve fuel consumption, you should use your brains from the above four aspects, such as discarding unnecessary debris in the car and reducing the weight of the car; using narrower tires to reduce friction on the road; if you drive a four-wheel drive, In general ON ROAD, you can choose two-wheel drive output driving; as for drivers, it is mainly used to reduce braking, reduce speed increase and maintain low-speed driving under safe and legal conditions.

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