Not sure I would call a diesel locomotive a hybrid. I would call it a diesel engine elctric CVT combo. In non-hybrid fashion, it dissapates braking energy in resistive heaters.

I call BS on the 80% efficiency, please provide your data.

I checked with my sources for this article.

It is difficult to make a general statement about the series hybrid having lower efficiency than other hybrids without considering other aspects of the hybrid system. Because none of the engine power goes directly to the drive shaft in a serial configuration and the full energy needs to be converted twice (once from engine power to battery power and the other from battery to motor output power), the efficiency of energy conservation from the engine output to the drive shaft will be lower than a parallel hybrid configuration. In a parallel/power-split hybrid, a significant part of the energy is directly transferred from the engine shaft to the drive shaft.

However, the series hybrid with Diesel engine, such as with a train, can have higher overall efficiency because the diesel engine can run at a constant speed at the most efficient operating point to charge the battery and that offsets the decrease in efficiency due to a double energy conversion. The same conclusion may not be true for series hybrid with gasoline engine.

In general, Buses use serial hybrids because they don't need high acceleration and there is not much limitation on packaging the many batteries needed to deliver full power.

Hmmm .... I'm not convinced a diesel-electric locomotive can be described as a hybrid as there is only one energy source being consumed at any instant, namely diesel fuel. The diagram of the series hybrid shows a battery present. This is able to contribute power at times of high loading.

Rather, a diesel-electric locomotive is really just a diesel locomotive, but one utilising the advantages of a flexible electric transmission, as opposed to a purely mechanical one. This technique extends to large mining trucks. Some manufacturers prefer electric transmissions, whilst others (eg: Caterpillar) prefer mechanical ones.

Actually its funny that your article is "out of date" with the current trends. First most people are moving to series hybrid, since with the proper "motor" controller design we can get rid of transmisiion loss. Also the job of the batteries is to provide the "everyday" drive, while the gas is for the once in a blue moon drive.

Look at www.acpropulsion.com, or www.teslamotors.com to see the future. Even GM now see's the light.

Power Steering is already full electric, braking is now or soon will be full electric. The 100 years of the internal combustion engine is starting to wind down

The serial-hybrid configuration does not suffer, "from lower efficiency and higher expense, because the system has two full-sized motors". Like anything else, it suffers from poor execution of design. Long before the word "hybrid" was in vogue, there were diesel-electric locomotives. While they weren't called hybrids back then, they were hybrids in every sense of the word. They existed because they are extremely efficient -- a typical hybrid locomotive is over 80% efficient. Both hybrid and non-hybrid vehicles have total efficiencies typically varying between 10 to 30% (the exception is the Prius, which varies between 30 to 40%). The biggest difference is the regenerative effect that can boost fuel efficiency, but only if you do a lot of coasting. Most people keep their foot on the pedal clear up to the stop light, so it isn't enough of a difference to justify the $5000 to %10,000 price penalty. The payback for that with gas at $3/gal is about ten years. For an example of a wonderfully executed serial-hybrid configuration design, search the internet for toyota volta on the ultimatecarpage. While it is expensive (which supercars generally are anyway, like the diesel-electric hybrid, it is certainly not inefficient).