All cars are divided into several categories and types. In the factory registers, each model is assigned to a certain class. Comparison of machines is subject to strict criteria. The class of small cars includes cars with engine power up to 90 hp, the class of racing cars differs speed norm above 240 km / hour. The representative class is a luxury car, soft and smooth on the go. Sports cars learn by the characteristic exterior, the swift lines of the low-seated body and the revolving motor.
Each car has a set of distinctive features. However, any model has the property of losing its attractiveness over time. Then the manufacturer takes up the upgrade. Comparison of machines that have already passed part of their resource with new models is usually not in favor of the former. In the automotive industry there is such a thing as modification. This means that any car can be modified with a change in design and exterior, but the brand, class and category of the car will remain the same. Sometimes the modification is cardinal, the car after the alteration changes its shape so that it can not be recognized. In case of profound changes, the car gets an additional name as a continuation of the main one, for example, Opel Cadet turbo, or Mercedes 220 cruise. There are countless varieties. It is the variety of modifications that makes it possible to regularly compare machines of different categories and choose the optimal options for further production.
Most often the new machine is created in three versions, the main difference between which is the body shape. This is a car with the bodies "sedan", "hatchback" and "wagon". The sedan is an all-metal body divided into three compartments: a motor for locating the engine with associated assemblies and units, then a driver's and passengers' saloon, and finally a luggage compartment. In passenger cars, the engine is always separated from the interior, the sealedness of the partition is a prerequisite for the characterization of the machine. The trunk of the sedan is also insulated with a special partition.
The bodywork of the hatchback is somewhat different. Engine compartment, like the sedan, is hermetically separated from the passenger compartment, but the trunk is a continuation of the salon space, the partition is not. The role of the partition is made by the back of the rear seat, but the separation of the trunk and interior in the body of the hatchback is purely conditional. From the seat back and to the luggage compartment glass, a horizontal panel of pressed fibreboard, pasted with dense matter, is installed. The fundamental difference between a car and the body of a hatchback from other cars is the shortened rear overhang and, as a consequence, the reduced volume of the luggage compartment. The advantage of the hatchback is the big rear door. With an open door it is convenient to load any loads.
Similar to the hatchback features have a station wagon, the body of which is designed according to the same scheme. Comparison of cars with a body "hatchback" and a body "versatile person" reveals essential difference. The wagon in the rear is much longer, which gives a significant gain in the amount of luggage space. The door of the rear aperture of the station wagon is located more vertically, and this allows extensive viewing. In some models, the rear door can be located in a sloping position, like a hatchback, but the rear overhang of the car in any case remains elongated.
This type of body is called "liftback". However, this type of special distribution was not received due to inconvenience when using the luggage compartment door. Comparison of cars by characteristics is the best way to determine the most successful designs. And if you use the results in the production that can be compared with the cars in terms of parameters, in the near future there will be new modern machines incorporating the best qualities of their predecessors.