low investment and high profit business Britain has a long history of motor vehicle development, and the world's leading enterprises, universities, motor racing industry and autonomous projects have the strength to realize the transformation and development. Professional knowledge and forward-looking thinking are the unique advantages of developing core automotive technology in the UK. In the American society of automotive engineers standards SAEJ 687 c for automobile is defined as: power driven by itself, with a driving device, can in a fixed orbit outside the road or on regional transport passenger and cargo or vehicle traction vehicles. Cars are divided into bicycles and trains according to the overall structure. Cycling is a basic form. 4 x 2, 6 x 4, 4 x 4 and 6 x 6 are used to represent the driving characteristics. The previous number represents the total number of wheels (double tire and still count a wheel), and the latter number indicates the number of driving wheels. If all wheels are driven wheels are called all-wheel drive vehicles. The train is made up of a tractor or a bicycle trailer or semi-trailer. Car generally can be divided into the following categories, according to the use cars, buses, freight cars (commonly known as the truck), off-road vehicle, traction motor, dump truck, special vehicles, semi-trailer and special semi-trailer. Currently, varied businesses are developing and booming on their own track. The idea that the priority of making profit precedes everything in businesses, has incited the reproach and criticism from the societies. As for me, I disagreed with this point of view as well, since the obsession on profits does damage to other things that a company request. I've been trying to get a refund because I collected more money and was turned down. It claims that I have been charged with the "cheapest" fare, although it admits that the price of the app is not correct. The car engine is in the design phase, and the fuel used for the compression ratio is set. The compression ratio is a very important structural parameter of the engine, which indicates the volume of the gas at the beginning of the piston at the beginning of compression and the volume ratio of the gas volume at the end of the piston. In terms of power and economy, compression ratio should be bigger and better. The compression ratio is high, the power is good, the heat efficiency is high, the vehicle acceleration, the top speed of the car will be improved accordingly. However, the compression ratio of the gasoline engine is not too large due to the performance of the cylinder material and the vibration of gasoline combustion. In short, a high compression ratio USES a high grade fuel oil. The higher the fuel mark, the slower the oil will burn, and the lower the combustion detonation, the higher the compression ratio of the engine. On the contrary, the low-grade fuel combustion rate is faster, the combustion explosion is large, the engine compression is lower.