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Quote (Jeff240sx @ Dec. 09 2002,8:07)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>
Quote (James @ Dec. 09 2002,8:37)</td></tr><tr><td id="QUOTE">--Does anyone know why turbo-diesels seem to be very efficient?--</td></tr></table><span id='postcolor'>
If I could talk to my friend right now, he could answer this.. but I can't, so I'll take a stab at it.
Diesel engines use heat plugs and compression to explode the fuel mixture, as opposed to electronics, low compression, and highly flamable gasoline. The rotating assembly on most turbo engines would astound you with their weight. They have a lot of rotational inertia and momentum to keep things moving. Also, turbochargers usually increase the efficiency of just about everything that they go on. A turbo uses heat to expand exhaust gasses that do nothing else but exit the tailpipe, to spin a compressor wheel and force more air into the cylinders than previosly possible. The turbo also draws air through the filter and feeds it to the engine, making life a little easier on the engine.
-Jeff</td></tr></table><span id='postcolor'>
Close, you also need to draw attention to the fact that a diesel uses ungoly compression ratios, like 15:1 and direct injection... When air is compressed that far, it is already damn close to combustion on it own, so you use direct injection of a SMALL amount of fuel and bang, there you have it. The engine does most of the work and needs only a little fuel to sustain combustion. The weight of the assemblies in a diesel engine are always much higher, but due to the fact that it all pretty much sustains itself, it can afford that tradeoff...