I'm all for a diesel hybrid too. A 1.5l 3-cylinder diesel could easily produce 100 hp on its own and add whatever electric to that for quite good performance. With a slightly diminutive Golf-like platform it would easily get 75 mpg in the city and 50 on the highway.
I would recommend reading the "Dashboard Hybrid Sales" report (Google it) because it includes hybrids, EV/plug-in, and diesel sales. So for February 2011, the numbers were:
23,263 (+19.5% vs Jan. 2011)
By focusing only on Otto vs Diesel cycle efficiency, diesel advocates often ignore: engine overhead and Atkinson efficiency. It turns out that four cylinder gas and diesel engines burn fuel at just about the same calorie rate when stopped. But then the hybrid cheats and 'shuts off' automatically and starts up when the gas is pressed while the diesel continued to burn fuel at the stop light. Furthermore, the 14 to 1 Atkinson expansion ratio and 8 to one compression ratio gives diesel-like efficiency in all but the highest, hill-climbing and pedal-to-metal accelerations. - Bob Wilson HSV AL.
Both Hybrids and super efficient diesels are stop-gap technologies. Even a diesel-electric hybrid would be the same. If we are running out of petroleum fuels, eventually neither will be a solution. Still, stop-gaps can help extend the time we have left.
Given the choice, I'd buy the efficient diesel. It just seems wasteful to purchase a vehicle with two power plants when a single-power vehicle with the same fuel mileage is available.
I never liked the hybrid nature of hybrids. Messy, heavy, expensive, dual powerplants involved. I'd prefer an efficient diesel any day.
But even better than that, I'm aching to see fuel cells, fed by something that separates the H2 out of fuel right in the car, and an all-electric powertrain. Heat pump for heating and cooling of the cabin. Can use biofuels or existing fuels, and certainly the existing fuel distribution systems. Should be at least twice as efficient as internal combustion engines. And if mated to a hybrid-car-sized battery, it could beat the pants of hybrid cars in terms of fuel economy and simpler mechanical components.
The most efficient engines in the world are all turbo-diesels. Although Atkinson-cycle gasoline engines can be nearly as efficient, this is true only in a relatively narrow "sweet spot" of operating conditions (which the hybrid system can optimize), while turbo-diesels are much more forgiving (not needing a hybrid as much...which allows simplicity and lower cost). see: http://autospeed.com/cms/title_Brake-Specific-Fuel-Consumption/A_110216/article.html and http://ecomodder.com/wiki/index.php/Brake_Specific_Fuel_Consumption_(BSFC)_Maps
Also, another "pet point" I'd like to make: Everyone always assumes that EV's are the end-game, yet they remain very far from practical for most people. With today's power grid sources, you are just trading one fossil fuel for another (oil vs. coal+natural gas). Net energy efficiency is no better than a conventional hybrid or turbo-diesel. Maybe in 30+ years the grid will be powered by primarily green sources. The best long-term solution (IMO)is to leave the cars alone, and focus further upstream by creating biofuels or solar synthesized fuels. see: http://cyber.mpnodes.info/archives/67 and http://www.sapphireenergy.com/green-crude/ then, we can keep the existing infastructure (gas stations, etc.) yet be zero-fossil-fuel, zero-net-CO2, etc. Cheers!
I've been involved with several military diesel hybrid vehicles over the past 10 years. The performance & efficiency offered for these extreme operating conditions is significant, especially when all the mechanical clap-trap is replaced with in-hub electric wheel motors.
It is true that hybrids are interim solutions but the point that has been missed is that this interim solution is a critical next step in the implementation of fuel-cell based prime movers.
I don't know how many more years will be required to make a fuel cell prime mover practical in passenger cars, but when they are available, it will be relatively simple to replace the CI ICE/ICE with the fuel cell.
Two optimum solutions exist:
hybrid diesel light - Add just enough electric assist to get regen braking energy and off zero starting and re-starting the diesel at stop and go.
2nd) Atkins cycle can be applied to diesel as well with some engineering challenges, but do-able.
Highest MPG and lowest emmisions AND CHEAPEST if done this way
If moderate or full hybrid lower emmisions are possible if engine kept running charging battery pack if not full. Warm up/shut down efficiency losses and emmision increases are minimised.
PS I am an EE but probably should have been an ME! Cool stuff
Diesel's Achilles' heel is that the fuel can get way too viscous in the winter time if you live north of the Mason-Dixon line. Now if a diesel vehicle had a self-start mechanism that would periodically kick in to warm up the engine and fuel system via some sort of heat transfer mechanism then this weakness would go away.
How about a propane fired pre-start for a diesel engine in cold weather? This can also be fired up to keep the fuel warm too.
However, most folks use electric block heaters in very cold weather. Why not use this approach to also heat the fuel?
Hmmm, could the fuel be used to cool the engine so the heat energy be recycled into preheating the fuel? Food for thought...
My 2005 VW Golf diesel starts just fine at -20°F without a block heater. Winterized fuel, a good battery and a healthy engine is all it takes. Since the engine is so cold-blooded, I don't get heat for several miles. That is easily cured by partially blocking the radiator grill - something the new Ford Focus does to speed its warmup.
An engine design which combines aspects of diesels and Otto cycle engines is the HCCI. http://en.wikipedia.org/wiki/Homogeneous_charge_compression_ignition This engine runs on gasoline or similar lighter fuel. It starts and idles with spark ignition, but, once warmed up, crosses over to compression ignition. I know Ford, GM, Mercedes-Benz, Honda and VW are working on them. This will be challenging to get right.
Lots of articles on new engine, hybrid, electric car and battery developments at
Basically, most people in the US think of only fossil fuel. No matter how clean the diesel engines get, they will still be fossil fuel engines. More progress must be made in the battery and alternate energy to make it viable primary means, not a viable alternate source. If more heads starts to think of this, we will be more close to the solution rather than diluting the efforts in all directions.
Picking the right tool for the right job, one needs to evaluate their urban versus highway driving. Brake pads, diesels wear them out and hybrids don't. Wearing out brake pads is the inertial penalty that diesels pay in an urban environment. In contrast, towns and cities are where hybrids and electric vehicles excel. But even on the highway, at best, smaller parity with a Prius.
Recently we had 112 hours of power outage in North Alabama when tornadoes sliced up the TVA power transmission lines. But our 2003 Prius with a 1 kW inverter ran burning about 2 gallons per day to provide lights, TV, radio, and the gas furnace when temperatures dipped down. The hybrid provides continuous power from the traction battery and runs the engine only as needed to recharge the battery. Unlike a generator, the catalytic converter eliminates the carbon monoxide risk, the muffler makes inaudible beyond our property line, and the 11.5 gallon tank holds enough to gas to run four days with 'no shutdown' refueling.
Since 2005 when I added the inverter, we have averaged at least one use per year for periods ranging from a couple of hours to over four days. But more importantly, the hybrid is becoming the core of home, co-generation, something a constantly running diesel will have a hard time matching ... if ever.
Japan manufactures the largest number of hybrids and the recent tsunami and earthquake has severely reduced production. However, with a six week shipping delay, the impact only started to show up in April and will be fully realized in May. On Friday April 29, my Toyota dealer was out of Prius.
It is very likely that hybrid production and sales won't recover until the fall. In the meanwhile, it is likely we'll see much higher mark-ups as supply dries up.
FWIW, alternative fuels are much better for air quality in either diesel or flex-fuel engines. When I switched to biodiesel, my opacity went from 8.0 to 0.9. That difference in air quality translates to better quality of life for those of us who breathe air.
I just don't understand why Americans don't like diesels when the rest of the world has already embraced them. When Americans think of diesel I'm sure more often than not they think of [url=http://www.stylintrucks.com]trucks[/url]. They are now very clean, not very noisy and not to mention diesel is cheap too. Carmakers should consider bringing their models stateside!