Friday, October 26, 2012

Diesels: energy-efficiency doesn't need excessive complexity

For a long time, Diesel has been the prevalent option for customers on the market for vehicles with a lower fuel consumption. From the old irons like the Fiat 128 to the current offerings such as the Fiat Punto Evo, in spite of all the emissions control devices which led to controversial effects in reliability, maintenance schedules, and even in the so acclaimed fuel-efficiency, such as the EGR which re-routes part of the exhaust gases to the combustion chambers in order to decrease the internal temperatures to reduce the Nitrogen oxides generation, Diesel engines are still the easiest way to conciliate performance with fuel savings.

One threat to the Diesels' supremacy are the hybrids, such as the Toyota Prius, but don't seem to justify all that "eco-friendly" aura implied by the marketing. Delivering fuel-efficiency ratings very close, often worse, their manufacturing processes have an increased environmental impact, apart from the higher technical complexity. An average compact car, such as the Chevrolet Cruze, easily delivers a higher mileage in Diesel versions.

Comparing to a gasoline-powered engine which would provide a close performance, Diesel has been less complicated, mainly due to the absence of an electric ignition system. Older ones, with a fully-mechanical injection setup, are able to remain running even after an eventual alternator failure...
Altough nowadays electronic fuel injections became prevalent, mainly due to the higher adaptability to environmental factors which influence the performance and efficiency, Diesels remain less complicated that any gasser.
Needless to say how simpler they are comparing to the hybrids with all the complex integration between both primary (combustion) and secondary (electric) drive and the high-voltage components...

There were also some few attempts to conciliate the higher thermal efficiency of Diesel engines with Hybrid drivelines, such as the Peugeot 3008 Hybrid4, but the overall cost still goes too high for the proposed improvements on the fuel savings, also becoming too opulent for a "world-saving" lurker, when some less expensive vehiches with close functionalities, such as the Peugeot 308 1.6HDI, can provide a lower overall life ownership cost from the first registration to the final disposal or a life-extending refurbishment...