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The use of air conditioning systems in passenger cars in Brazil has increased significantly in the last decade. The installation rate increased from 47% in 2006 to about 80% in 2012. Especially for compressors with variable displacement, the measurement of the impact of this equipment on the engine performance and on the fuel consumption represents a challenge to be overcome. It must be considered that the environmental conditions present a great influence on the heat load to be removed from the passenger compartment. This paper describes the development of an experiment at an engine dynamometer bench to simulate the influence of the air conditioning system on the engine parameters. The combustion engine works with the compressor and all the others air conditioning system components assembled.

The introduction of the flexible fuel vehicles in Brazil had the first objective to protect the customer against fuels - commercial gasoline (E22) and hydrated ethanol (E100 or AEHC) - price variations. Nevertheless, while the Flex technology became dominant in the Brazilian market, the environmental aspect of the possibility of using a renewable fuel, ethanol from sugar cane, increased in importance due to the reduction in non-recyclable CO₂ and its benefits for the greenhouse effect. The objective of this article is to propose a practical method to quantify the avoided CO₂ using available engine management system parameters, basic chemical calculations, literature information and simplifying assumptions. The resulting equations show that it is possible to have a practical avoided-CO₂ calculation procedure which can be performed on-board and used for customer information and for quantifying the environmental advantage of using ethanol in fleets of flexible fuel cars.

The search for better energetic efficiency of the flexible fuel engines will guide the next design changes in this technology. The use of direct injection and the downsizing of volumetric displacement compensated by supercharging is a possible solution to reduce the fuel consumption. The direct injection brings the thermodynamic benefits of the charge cooling; the reduced displacement reduces the pumping work in partial loads and engine friction, while the supercharging allows the performance of a bigger engine. The combination of these technologies with hydrated ethanol (E100 or AEHC) represents a performance and CO₂ reduction opportunity, but also a challenge in terms of cold start and durability. The objective of this study is to evaluate and compare the behavior and the potential in full load conditions of an engine equipped with direct fuel injection and turbocharger, using Brazilian Hydrated Bioethanol (called as E100) and Brazilian gasoline (called E22).

Due to the increasing importance of vehicle energy efficiency, design changes on flex fuel engines aiming fuel consumption and CO₂ emissions reduction becomes priority. It is known that, due to chemical difference between hydrated ethanol (E100) and commercial gasoline (E22), parameters as combustion pressure, burn speed and knock tendency vary according to the fuel and are decisive for the engine thermal efficiency. This study has the objective to show and quantify the influence of the cooling liquid temperature in these parameters and on the thermal, mechanical and global efficiencies of an Otto flexible fuel engine, aiming to observe opportunities of fuel consumption reduction and performance improvement, as a way to compensate the fixed compression rate of flex engines. The results show that it is possible to have better efficiency in partial and full loads, adjusting the cooling liquid temperature according to the used fuel.

Fuel consumption and CO₂ emission are important drivers of automotive industry product evolution. In Europe, the manufactures have the compromise to reduce their fleet consumption steadily and, in Brazil, a still voluntary but growing labeling program makes the vehicular energetic efficiency one of the main concerns during the concept phase. Different from the full hybrid technology, where the car can be driven purely by the electric motor, the mild hybrid has been mentioned in literature as cost-effective route to reduce CO₂ emissions through the combination of a highly responsive low power electric motor, which acts supporting the internal combustion engine in special driving situations, with energy recovery and storage system composed of advanced batteries. Therefore the mild hybrid system can be understood as one type of downsizing strategy.

Fuel consumption and CO₂ emission are important drivers of automotive industry product evolution. In Europe, the manufacturers have the compromise to reduce their fleet consumption steadily and, in Brazil, a still voluntary but growing labeling program makes the vehicular energetic efficiency one of the main concerns during the concept phase. Although powertrain efficiency plays a decisive role, also vehicular parameters such as weight, aerodynamic, tires rolling resistance and electrical and mechanical loads have an important influence on fuel consumption and CO₂ emissions. The cost-benefit analysis of the modifications in these parameters needs to be performed in the early project stages, where prototypes are still not available.

The introduction of the flexible fuel vehicles in Brazil had the objective to protect the customer against fuels - commercial gasoline (E22) and hydrated ethanol (E100 or AEHC) - price variations. One of the first questions of customers is therefore which fuel is the best to use in terms of cost per kilometer. The car manufacturers usually have a thumb law in that it is worthy to run with E100 if its cost is up to 70% (a number called "advantage factor") of the E22's. The objective of this article is to study more quantitatively in which driving conditions this assumption might not be valid. Additionally, an estimation of the non-recyclable CO₂ emissions with both fuels is performed. The results show that, depending on the ambient temperature and driving cycle, the known advantage factor can present a different value, affecting the customer decision.

The durability certification is one of the critical paths of a mass production vehicle project. For structural components, the development and the execution of experimental tests supported by finite element method (FEM) became mandatory for implementation time reduction, especially when on-board diagnoses (OBD) legislation turns even small cracks in severe structural failures. This job aims to show a simulation method of structural efforts in an exhaust system on a test bench. The exhaust pipe is previously analyzed with FEM and the critical points are instrumented with strain gage in vehicles. The strains are measured and its values reproduced in a dynamometer bench using a shaker with adjustable amplitudes. Therefore, difficulties to reproduce temperature and strain were overcome and the test shows repeatability. The variation of shaker device amplitude makes it possible to define the life cycle curve of the part.

The advent and high market share of the flex fuel were viable also due to the use of software to identify the type of fuel via the oxygen sensor signal manipulation. However, these routines are subjected to a non observable system, especially in conditions where the fuel enters the combustion chamber by ways other than the injectors, as the blow-by system, which leads the gases from oil pan. These gases can present high alcohol concentration, which evaporates from the contaminated oil, mainly after starts at low temperatures, causing the shifting of the oxygen sensor signal and consequently the misinterpretation of the fuel type flowing into the engine. This paper has the objective to propose an estimation method for the mass of fuel in the oil, using separate simplified physical models for the oil contamination and for the alcohol evaporation processes.

The introduction of Flexfuel technology in Brazil in 2003 brought an unquestionable advantage to reduce the emissions of greenhouse gases in automobiles when used with ethanol. Furthermore, the research to increase the efficiency in the use of renewable energy is crucial for the sustainability of the automotive industry. Among the feasible technologies for achieving this goal, the Direct Injection Spark-Ignited engine (hereinafter referred to as a DISI engine) and the turbocharger are the most promising in short and middle terms. The combined use of Direct Injection and turbocharger on an engine can promote the downsizing. Both technologies are closer to the Brazilian reality and the Turbocharged DISI engine can even more be improved when used with the biofuel ethanol through its inherent thermodynamics advantages.