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A friends TDI Jetta is returning between 40-50 mpg. As we all know diesels traditionally get metter mileage so this got me wondering - has any company experimented with a diesel hybid? I know it would not be as environmentally friendly but may get even better mileage than its gasoline brethren.
 

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Also hybrid doesn't lend itself to diesel as well.

One of the benefits of hybrids is the relatively poor low end torque of a gasoline ICE. The electric part of a hybrid dovetails nicely with this deficiency. A diesel's low end torque is where it shines :!:

And diesel being more fuel efficient to begin with will exhibit less MPG benefit with being hybridized.

Diesel having a _much_ higher compression ratio than a gasoline ICE the hybrid part would have to be correspondingly larger for the required extra "grunt". So unless you go with the "Toyota" type of hybrid there is this third drawback to the marriage.

Finally the cost effectiveness / pay back time will be _much_ longer with a diesel.

But from an emissions perspective of course anything that reduces ICE on time is a benefit as long as the pollutants emitted in the creation, maintenance and disposal of the added technology don't exceed this obvious front line savings.

HTH! :)
 

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That's not at all my experience with diesels - though I admit most of my hands-on experience is with trucks and equipment, not auto.

I think a diesel hybrid would work well. Diesels like to run at constant speed: watch a semi or construction equipment, and notice that the times when the black smoke comes pouring out is when load is added, and the engine lugs a bit before getting back to its preferred steady state.
 

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Constant RPM is _true_ of _all_ ICE's regardless of fuel type. As long as your running them in their "sweet" spot.

Take a look at the torque / RPM curves of any diesel and compair it to a similar sized gasoline engine ;) :!:

Yes, a diesel hybrid should be better, just not as *much* better as a gas hybrid.
 

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Yah :!:

But how much is the battery pack :?: :p (That one's gotta HURT)

Seriously. I was wondering about this myself a couple of years ago. A neighbor is a railroad engineer. (A train driver not designer.)

We were talking and he was explaining the mechanicals. Currently the "braking" energy is simply dumped into a huge "resistor" (heat sink). Glad to see hybrid locomotives coming in the future :!:
 

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As the owner of a diesel AND a hybrid, I can tell you that combining the two would create pretty much my dream car. And the main reason is that I could run it on biodiesel and get off the petroleum bandwagon for good. I already run biodiesel in my Benz wagon and it's an incredible fuel. I get 28-30 mpg highway on biodiesel in a 2-ton, 20-year-old wagon. Hybridize a similar car with a modern direct-injection diesel and you can imagine the possibilities (i.e. -- a hybrid VW Jetta tdi wagon could approach 70 mpg without any other mods).

What I've heard is that combining the extra cost of a hybrid with the extra cost of a diesel is just prohibitive in the market. I don't buy that, because plenty of people willingly drop $40k+ on massive SUVs that get 20 mpg. What needs to happen is for the gubment to impose steep mpg standards on all vehicles, which would drive the carmakers to build cars like this.

The thing that kills me is that this is all existing technology. When you hear politicians say a 70+ mpg car would be dangerous because it would have to be small, you know it's nonsense. They're just defending the carmakers who don't want to cut into their mountainous profits to build anything innovative.
 

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It would be pretty expensive to electrify trains in the west. As you know, places like Reno are a long way from anywhere else! Here are some pictures of coal trains in Colorado; consider the cost to put up the wires (and maintain them) and also the distribution loss. Until we run out of diesel oil, it's a pretty good way to power a train...
http://www.mtnwestrail.com/roadtrip/sept0499.htm
 

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Actually Diesel Electric hybrids were the first hybrids. I drove diesel electric subs which have been around for over 100 years. Ofcourse the 500+ tons of battery is a bit excessive for personal use. Have fun, Rick
 

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Hybrid and diesel does indeed go well together. Nissan sells a diesel hybrid truck to the Japan market which gets 50% improved fuel economy over the non-hybrid version.

As for future diesel-hybrids in the passenger car market, several manufacturers have well advanced demonstration vehicles that look pretty close to production.

Eg Mercedes have several well-advanced diesel hybrids, GM have the 0-60 in less than 8sAstra diesel-hybrid and Toyota have the Yaris/Vitz based 87 mpg ES3.

The only thing holding back production of these vehicles is cost. Fuel prices need to go higher or hybrid component prices need to come down before they will commit to marketing them.
 

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Thanks for your post Clett, I wanted to find those examples for everyone but didn't have the time.

I personally think diesel-hybrids would rock. :D
 

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Diesel hybrids may not be too far off...over the past few days I've seen articles talk about VW working with the Chinese and with Porsche to make a hybrid engine...maybe they work more toward a diesel hybrid as opposed to just a hybrid.
 
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