Running at high speed of 120km/h, what is the speed of your engine? Is the lower the speed of the car better?
Speed and speed is actually not a positive correlation, in general, the speed will reach the lowest value of the speed after reaching 60-80km/h, and then speed up, the speed will often climb, in general, ordinary family cars 120km/h cruise when the engine speed is between 1200-4000 rpm are normal values, the specific speed depends on the specific model.
Run models with lower high speeds
1. Models with more gears and a wide range of transmission ratios
In general, models with higher gears have the conditions to achieve lower speeds at high speeds, and although the gear of the gearbox is not the only determining factor, the influence on speed is very critical. In general, the higher the gear of the model, the wider the range of gear ratio, for example, Toyota's 5MT top gear ratio is 0.775, Volkswagen DQ200's highest gear ratio is 0.795, ZF8AT's highest gear ratio is 0.667, General and Mercedes-Benz's 9AT highest gear ratio is about 0.6, ZF's 9AT highest gear ratio is 0.48. In the case of a similar power level, the lower the transmission ratio of the highest gear, the lower the speed.
2. Models with strong power and wide torque platform
Generally speaking, under the same conditions, the stronger the power, the lower the peak torque speed, the lower the speed of running high speed. This is due to maintaining a speed of 120km/h, the car needs to maintain a certain amount of power to overcome the huge air resistance, while the power, peak torque platform wide model, only need a lower speed to get enough power, and turbo models have more advantages in this regard than naturally aspirated models. GM models such as the LaCrosse have a speed of 120 per hour, and the speed is usually around 1700 rpm.
3. Models equipped with low-speed engines
In addition to the influence of power parameters and transmission, the type of engine will also significantly affect the speed, just like the honda's famous redhead machine before it is a high-speed engine. High-speed and low-speed engines are like a fat and a thin two people filling water, and the fat man takes a large bucket, which is loaded more at a time, but the speed of loading is slow. The thin man takes a small basin, and loads less at a time, but the speed is fast and diligent.
Models with high speeds
1. Small displacement self-priming engine
Many small displacement self-priming engines roar and do not go, in fact, because the power is weak, to achieve enough torque must hold the speed, so to maintain a speed of 120 per hour, the speed is generally higher.
2. Manual transmission model
In fact, as long as you are willing, you have not been upshifting, you can always keep driving in the red line zone, but for a long time, the engine can not stand it. And the general manual transmission has only 5 gears, the transmission ratio is relatively narrow, for example, Toyota's 5MT highest gear transmission ratio is about 0.775, the speed is about 120km/h, and the engine speed is about 3000 rpm.
3. Models that focus on low twist such as vans
In addition, if you run through the high speed with a van, you will find that the speed of your car is particularly high. That's because the van is often fully loaded, and it is more advantageous to have a low torsion, how to achieve it? It is that the radius of the low-speed gear is often adjusted to a relatively large, the transmission ratio is relatively large, resulting in a high-end transmission ratio is also correspondingly larger, so the 1.2L van often has a speed of less than 100 per hour, and the speed has exceeded 3000 rpm.
4. Models equipped with high-speed engines
In addition, there are models equipped with high-speed engines, such as Honda's K20A is a famous high-speed engine, it takes 6100 rpm to burst out the maximum torque of 196 Nm, the maximum speed of 8600 rpm, slightly deep throttle, immediately downshift, the engine speed soared.
Although the speed of running high speed is not the most important reason to judge the quality of a car, it can be seen from the above that the model with low speed is either a model with strong power or a model with more gears, in general, if it is lower than 2000 revolutions, it can basically be said to be a good car.