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Mercedes today has officially taken the wraps of their newest diesel engine generation – one that will be launched starting in autumn 2008. While the new engine will replace four of Mercedes' current diesel powerplants and be featured on a number of different Mercedes models, including the E-Class, the GLK-Class and the E-Class Coupé (yes, you heard me right – an E-Class Coupé is coming), the engine will first make its debut on the new C-Class pictured before you: a model that's being called the C 350 CDI BlueEFFICIENCY Prime Edition. And I have to tell you, the figures are impressive, to say the least.

http://emercedesbenz.com/Sep08/10_00...e_Edition.html

 

Well, this is certainly great news but nothing really exciting or groundbreaking to be sure. Where is the diesel/electric hybrid? Why are the Germans behind on hybrid technology? If BlueTEC is so smooth and advanced it can surely bepaired with electrics in a hybrid to deliver higher MPG than a gas/electric hybrid. Time to step up the your game M-B.

 

Behind on Hybrid Technology?

The reason for hybrid technology is that the gasoline engine runs at lower and lower efficiency as its output power is reduced.

This is because the "throttle" does just that: reduces the amount of air reaching the cylinders, and therefore lowers the compression ratio, reducing efficiency. Best efficiency is obtained at full power only.

A hybrid makes the best of this by only running the engine at full throttle and controlling output to the desired amount by either supplying power from the battery, or putting power into the battery.

In addition, the Prius for example has a low frontal area, very slippery body, and hard tires; making for a high-mileage but uncomfortable car.

A diesel engine, on the other hand, does not run at reduced efficiency as the fuel is reduced; the full charge of air is still going into the cylinders, even though there is less fuel to burn in it. There is much less to be gained by adding the electric motor and batteries.

Regenerative braking is lost, but it is of no value on the highway and not much in town, despite its appeal to buyers.

I like a lot of cylinders, (I just barely managed to keep myself from buying a V-12 recently), but as every engineer knows, you get more power with less weight using fewer, larger cylinders. If it is well engineered, it will deliver M-B smoothness and reliability. Time will tell.

Meanwhile, I wonder how well a Prius would do with a small diesel instead of all the gadgetry?

I know lots of people with hybrids, they are very popular in the DC area, and no one seems to be getting the fuel mileage expected. Whereas I get a solid 33 mpg on the highway in a comfortable, safe, and elegant 300 turbo diesel.