At a speed of 120, what rpm is considered a good car?Veteran driver: Remember this number, just keep it smaller than it

Some people hear vehicle speed and rotational speed and think that these two are increasing year-on-year. In fact, it is not that simple. There is also a relationship between torque, gear, transmission form and ratio, and there is no absolute relationship between rotational speed and fuel consumption. The relationship between the two is also very complicated, but for ordinary car owners, the speed can simply measure the fuel consumption at that time. For example, at a speed of 120 kilometers per hour, the speed from 1500 to 4000 rpm is normal, and different models will have different performances. This is also related to the core adjustment of the car. So for a speed of 120, what is the speed? Nice car? Veteran driver: Remember this number, just keep it smaller than it. First, for manual transmission models, vehicle speed = 0.377 * rotation speed * tire dynamic radius / transmission ratio. It can be seen from this formula that as long as the value of the transmission ratio is smaller, it means that the rotation speed will be lower, such as a 5-speed car Looking at the transmission ratio of a manual transmission, when the vehicle speed is about 120 kilometers per hour, the engine speed is about 3,000 rpm. That is, the same vehicle speed will be lower when the gear is higher. If it is 3rd gear and reaches 120 kilometers per hour, then The speed will soar to 4500 rpm. Second, for small-displacement self-priming engines, generally speaking, smaller-displacement models have higher speeds at high speeds. The reason is also very simple. With a small displacement, the power of the car is relatively small, and if you want To increase power, you must increase the speed, such as a combination of a 1.2L self-priming engine and a 5MT or 4AT. Third, high-speed engines, such as Honda's K20A, this red-headed engine has a displacement of 2.0, a maximum horsepower of 220PS and a peak torque of 196 Nm. The maximum speed reaches 8600 rpm. This is an ordinary model. What it doesn't have, coupled with Honda's special technology, can easily reach 7,000 rpm. Fourth, cars that focus on low torque, such as light trucks, vans, etc., although the displacement is not very large, because they must be more powerful to pull goods and passengers, so the radius of the gear of vans is generally It will be designed to be large, so you can feel the relatively large output at low torque. However, the engine is relatively weak at high speeds, and the speed can reach 3,000 rpm at 80 kilometers per hour. When running at high speed, the speed is relatively low, such as the platform with strong power and maximum torque is wide, but the power is relatively strong and the speed is low at high speed. It is enough if the platform is wide, such as 250NM peak torque, 120 kilometers. A turbocharged engine will rotate at a lower speed. Because the maximum torque is reached relatively late, the speed can be increased without increasing the speed.For example, a low-speed engine is like a water cylinder. Some people use large buckets to fill it, and some people use small buckets to fill it. Low-speed engines use the method of increasing the stroke to reduce the speed. The high speed is lower than 1200 rpm. is a good car. Do you remember this number?