So Diesel is more fuel efficent than gasoline. Why don't we have Diesel - Hybrid Electric Cars?

Well, as usual, Europe is waaaay ahead of the US in all areas.

http://www.citroen.com/CWW/en-US/TECHNOLOGIES/ENVI...

or this one really looks fun!

http://video.google.com/videoplay?docid=7138627739...

all this going on while the US auto makers sit on their thumbs pushing big boxy SUV's and an electric car that looks like road kill that you can plug in for maybe 40 miles range...ugh!

Diesel engines inherently rely on adiabatic heating of air at high compression ratios in the cylinders. The thermal mass of the engine block inhibits the efficiency of diesel engines until the temperature of the engine block has reached thermal equilbrium during operation. Accordingly, it's often preferable to keep diesel engines running, rather than shutting them off, especially in colder climates. For that reason, it's not uncommon to see semi trucks and construction equipment with their diesel engines left on even when they are not being used.

On the other hand, gasoline engines jump to life with merely a bit of fuel and a spark, so they are much more suitable for the intermittent operation experienced in a hybrid vehicle. As newer hybrids are developed that electrically separate the internal combustion engine from the drivetrain, diesel engines would start to become more suitable for use in hybrids, in a manner similar to diesel-electric railroad locomotives.

Also GM has created a technology called Homogeneous Charge Compression Ignition that will allow gas engines to operate like a diesel (ignition without a spark plug). That will boost efficiency by ~15%. No word on how much it costs though.

Oh and here is a great video explaining why diesels are not popular in the US. http://youtube.com/watch?v=xXA22Q0qXNM

If you paid any attention, we already do. Mercedes has released its first line of diesel cars this year, and it is very very clean. Mercedes is using tail pipes that contain chemicals that effectively clean and scrub all gas emissions. Expect to find diesel hybrids soon. Diesel is also stronger and is more fuel efficient.

diesel engines are more efficient, and they are more suitable for the use of bio oil as fuel, but they are also more expensive, which makes Diesel powered cars more expensive, so people, when considering which car to buy, usually opt for the cheaper car and expensive fuel option.

i will anticipate that is a hybrid, wherein case that is going to take gas. however the undesirable information is, you may purchase a diesel automobile greater interior of your potential and get merely approximately fairly much as good mileage as a hybrid, without the eventual cost of batteries.

diesel wont pass Ca emission standards, and is too heavy

Deisel is still more dirty than unleaded.