The paper considers the problem associated with the dependence of fuel consumption and CO2 emission by automobiles on their characteristics such as mass, class, engine displacement, transmission and type of fuel used. Automobiles of various classes offered in Lithuanian market were investigated from the above perspective. The main factors determining different average fuel consumption and CO2 emission by these motor cars were identified. Some measures of reducing automobile fuel consumption and CO2 emission are offered.

Abstract. For examination of road accidents often calculations are being performed according to mathematical equations having many variables, real values of which are of stochastic nature and they depend on many accident factors. Therefore it is important to know limits of determination of final values of every being analysed parameter of car movement and their probabilistic characteristics. This paper presents some cases of simulation of some road situations by mathematical methods of calculations, which now are widely used for evaluation of accuracy of values of the calculated parameter (in this paper -the braking distance). Also here is presented some analysis of these methods. The paper presents the following cases of car braking: braking with making attempts to prevent a collision with another car, braking through impact-to-pedestrian prevention and conventional (rectilinear) car braking. The main attention in the analysis of the mentioned road situations is paid to veracity of the car braking distance, i.e. to limits of variation of values of this parameter and also to influence of accidental factors on the final result which is being looked for. Some conclusions on the expediency of application of the described methods of calculations to analysis of road accidents are present.

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This article analyses the factors that considerably influence the efficiency of automobile technical exploitation. It has been noted that automobile technical exploitation is basically determined by the following factors: the system and organizational level of automobile technical maintenance and repairs; the level of service basis; qualification of the staff; the level of stock and supply; the structure and age of automotive fleet and conditions of exploitation. This article presents the analysis of the first factor. The factor is significant enough and does not involve big investments. A theoretical analysis of the system of automobile technical maintenance and repair has been carried out. According to the nature of automobile technical maintenance and repairs two strategies are possible: the planned-preventive and the mixed type. Applying the first strategy the exact number of operations is being planned ahead, but the amount of work remains unknown. According to the second strategy the technical condition of an automobile has to be checked before starting technical maintenance and repair and only then the exact number of operations can be defined. The second strategy makes it possible to save spare parts, materials and time. This strategy, however, can be applied to the automobiles that are in good technical condition. The analysis of automobile technical maintenance and repair organization has shown that in order to improve the efficiency of automobile technical maintenance and repair the laws of mass service theory should be applied.