Does Increasing ICE Engine Efficiency Lower Exhaust Temperatures Proportionally?

[neen]

So the current estimate is that an ICE engine is about 20%. If we were able to increase the efficiency of a given engine, would that result in a proportional decrease in exhaust temperatures? (Given that driveline loss to friction is constant)

 

[CWatters]

Perhaps.

https://www.physicsforums.com/showthread.php?t=280572

 

[CWatters]

Also worth noting the section here on pumping loss..

http://prius.ecrostech.com/original/Understanding/InternalCombustion.htm

 

[mrspeedybob]

It would depend on how the increase was achieved. An ICE emits waste energy not only through the exhaust but also though the radiator and directly to the air. If the efficiency increases, the decreased emission of waste energy could be in the form of reduced exhaust temperature, reduced exhaust volume, reduced heating of air via the radiator, reduced heating of air via circulation through the engine compartment, reduced noise or vibration, or most likely several of the above.

 

[sardar]

I can provide an explanation for the relationship between engine efficiency and exhaust temperatures in an ICE engine. It is important to note that the efficiency of an engine is determined by the amount of energy from the fuel that is converted into useful work. Therefore, increasing the efficiency of the engine would result in a proportional decrease in the amount of energy lost as waste heat in the exhaust.

This is because a more efficient engine would convert a higher percentage of the fuel's energy into useful work, leaving less energy available to be released as heat in the exhaust. However, it is important to consider that other factors such as combustion efficiency and engine design also play a role in determining exhaust temperatures.

In addition, a decrease in exhaust temperatures may also be influenced by the driveline loss to friction. This is because a more efficient engine would require less fuel to produce the same amount of work, resulting in less friction within the engine and potentially lowering exhaust temperatures.

Overall, while increasing the efficiency of an ICE engine may result in a proportional decrease in exhaust temperatures, it is important to consider all factors that contribute to exhaust temperatures and their potential impact on engine performance. Further research and development is needed to fully understand and optimize the relationship between engine efficiency and exhaust temperatures in order to improve the overall efficiency of ICE engines.