We usually applied to the tire on the ground is referred to as a power wheel power. I.e., the rotor power is reflected on the wheel, the transmission process of the engine, because a portion of friction losses, the engine power is greater than the direct transfer wheel power!
1. The power on the wheel noun
We usually applied to the tire on the ground is referred to as a power wheel power. I.e., the rotor power is reflected on the wheel, the transmission process of the engine, because a portion of friction losses, the engine power is greater than the direct transfer power to the wheel.
2. The power of the engine power and the difference between the wheel
It is well known gasoline engine gasoline chemical energy into heat, and then part of thermal energy into mechanical energy to drive the vehicle. This in itself is not a very good way of working, because a large part of the energy released into the air through the form of heat. The rest is converted into mechanical energy but also as a generator, hydraulic power institutions and to provide power for cooling systems and air-conditioning and so on a range of devices, etc. These devices have been part of the power that they need later, and the rest is from the crankshaft output power to drive the vehicle, which is currently the majority of manufacturers in the publicity color pages nominal power parameters, that is, the power output from the engine crankshaft.
However, the fact is that so far you can see the power value ratio like fuel consumption as published by manufacturers, will never get in everyday use, since the transfer of power is not over yet, from the engine crankshaft to the car the tire eventually reach the ground is a long journey full of gears and bearings. Imagine, first clutch or torque converter, then the transmission, final drive, differential, axle, and finally to the wheels, the tires to transmit power to the ground … I’m too lazy to go to the complicated process of breakdown All in all reality be more complex than I would only say. In this process, the power will vary because of mechanical efficiency loss, power is transmitted through these final action on the ground is what we really can use to power.
3. Calibration factors affecting manufacturers of power on the power gap with the wheel
● efficiency of the transmission
As we all know, the mechanical efficiency of an ordinary automatic transmission is generally lower than conventional manual gearbox, the car equipped with the same engine, automatic models top speed may be slightly slower than the manual transmission models but also some of the more costly oil.
● manufacturers engineering
This is a complicating factor, give a relatively simple example, after the pre-drive vehicles because of the layout of the power transmission process is more complex than the previous drive , mechanical efficiency is slightly lower than the previous drive so little, although only a small point. In addition, because the tire on the wheel power is power on the ground, grip is essential, so what type of tire with a tire factory is also noteworthy.
● manufacturers Determination power
different manufacturer for the “maximum power” is understood that there are differences, for example, some manufacturers will be tested in the case of connecting the generator, cooling system load during the test the maximum output power of the engine crankshaft, and some manufacturers will likely remove these loads, engine maximum power draw value to a more idealized. In this way the latter is clearly nominal power will be relatively larger, while the power of the actual test wheel is relatively small.
● external environmental factors other factors
the air temperature and humidity can also have an impact on the power, many manufacturers in the calibration of the engine at the right most beneficial calibration environment of the engine power output, such as fuel pressure, temperature, humidity, lubrication, high calorific value, reduce exhaust back pressure, etc. these conditions are laboratory conditions, it is impossible to achieve in everyday use in the car.