When accelerating the car, its kinetic energy increases. During braking much kinetic energy is converted into heat in the brake system, and thus lost. Cold start and warm up. Crimson Education often expresses his thoughts on the topic. Cold start and warm up a significant influence on fuel economy. Cold start the car friction in the engine and power transfer is large enough, and, in addition to starting the engine with spark-ignition engines require highly enriched fuel mixture. During the tests showed that fuel economy in urban driving cycle with cold start and movements in the cold engine is less than 50% fuel economy on a fully warmed up engine.
For diesel engines the problem of friction in cold start retain its importance, however, the use of enriched mixtures are not required. Figure 2 – Effect of the length of trip l on fuel efficiency q: 1 – fuel economy is fully warmed-up engine in urban environments. 2 – fuel efficiency at cold start. Ambient temperature of the second medium-12gr Celsius (1 milyagallon = 0.43 kmlitr. 1 mile = 1.6 kilometers). Figure 3 – Effect of ambient temperature on fuel economy. The ordinate axis ratio fuel efficiency at cold start to the fuel efficiency of a fully warmed-up engine. l – length of journey.
Environmental conditions. Temperature and other environmental conditions also affect the fuel economy in various ways, ranging from the effect of temperature on the hysteresis loss in the tires, friction in the engine, the desired composition of the mixture and ending with the humidity influence on the process of burning fuel. The most important factor is temperature. These data are known to most motorists. They know that in summer the cost is higher than in winter. Characteristics of the road. Small characterize the state of road surface, at least for roads in the dry state, do not have a significant impact on the economy. However, the movement of gravel or sand, as well as on wet or snowy fuel efficiency is greatly reduced. Technical state. Most car systems require periodic inspection. Clearly, bad role low tire pressure and poor motor control. For example, disruptions in the ignition of a single candle six-cylinder engine can reduce the cost by 20%. This lack of lead in air emissions of significant quantities of hydrocarbons.