Is there something wrong with deisel hybrids? Do deisels not idle at stop lights? Would they not benefit from regenerative braking? These are not competitive solutions. They are two different choices for future efficiency gains that can be complimentary.
For that matter, hybrid technology makes sense for ethanol too.
I see no reason why hybrids won't continue to gain marketshare even among deisels. Even deisel or ethanol gensets for PHEV's make sense.

That begs an interesting question, from a CO2 standpoint, which emits more CO2, a gallon of diesel or a gallon or gasoline?

Darwin, you're making too much sense.

But, doesn't it take more oil to refine a gallon of diesel than a gallon of standard grade gasoline?

No, just the opposite.

How do diesels compare from a well-to-wheels point of view?

Better.

Also, is the clean-diesel tech clean enough?

If it isn't, neither's gasoline, especially the way gasoline technology is going (stratified charge lean burn)

Nothing on the table right now is a game changer. Everything on the table still play by the same rules, and it's by those rules that we need to figure out how to encourage people to drive more efficient vehicles.

It is also clear that a gallon of diesel contains more ENERGY than a gallon of petrol.

The other reason why you don't have diesel hybrids is cost. The fuel injection and aftertreatment systems of a modern diesel are not cheap (esp if it is to meet T2B5). As a result of this and the fact that a diesel is a better compromise than a petrol hybrid under most circumstances make a diesel hybrid less likely.

If a move to diesel slows or delays the implementation of PHEVs by reducing the adoption of HEVs then this is not good. While diesels are better than gasoline cars, there still remains to major problems. One: they still get all of their motive power from fossil fuels, mostly oil. Two: now we have even more direct competition between private, often unnecessarily driven, LDVs and the delivery trucks that brings our food to market.

During the 90's GM, Ford, and Chrysler independently arrived at similar conclusions to meet PNGV's family sedan challenge: light weight, diesel-electric hybrids.

Cost is the detractor:
If a clean turbodiesel adds $2,500 to the cost of a vehicle, and hybridization adds another $4,400- how many consumers are willing to fork over $7,000 in the name of fuel efficiency? (notice, I did not take into consideration the cost of lightening vehicles- a fuel saving measure that, to date, has not been expolited)

What does the $7,000 price premium buy the US consumer?
Take two identical vehicles: one with a conventional 30mpg drivetrain, the other with a 70mpg diesel-electric drivetrain. Driving both 15,000 miles per year, while paying $4/gallon for fuel:

70mpg diesel-hybrid requires: 214.3 gallons or $857/year
30mpg conventional drivetrain: 500 gallons or $2000/year

At $4/gallon it would take over 6 years of driving to recoup the $7,000 price premium for the diesel hybrid.

This is where tax breaks and subsidies would help. From a National Security perspective cars using 214 gallons/year are much more favorable than 500 gallons per year, let alone over 700 gallons a year (as present US fleet average fuel economy dictates).

Andrey, I note you're using weight and not volume or energy. Anyway, if you fractionally distill a barrel of oil you'll get 5-20% diesel (depends on crude), which you test for cetane and maximum sulfur (again, depends on crude), and that's it. You will get no gasoline. To get gasoline you have to make it, which means combining the naphtha (which you do get) with fractions (some naphtha, some heavier) you isomerize and fractions you crack into small aromatics. Demand being what it is, you'll likely also crack heavier fractions into naphtha. Then you combine it all, check for octane and max sulfur content. The additional processing steps of cracking and reforming all take energy.

If a move to diesel slows or delays the implementation of PHEVs by reducing the adoption of HEVs then this is not good. -- Neil

Agree 100%. It's hard to see that ICEs will go away in the next couple of decades, so hopefully maturing technology will significantly lower the premium for diesel hybrids. Preferably serial, Volt style. And hopefully all urban traffic will be electrified.

Diesel answers no long term questions. If the Peakists are eventually correct, diesels are not the answer. If the atmospheric concerned are eventually correct, Diesel is no long term solution there either. -- Stan Peterson

Good Lord. I agree with Stan Peterson!

bad news- according to the American Petroleum Institute, most of the refineries in this country are optimized to produce gasoline (despite as coal burner correctly points out, the fact that there is less gasoline available in a barrel of oil than diesel.) And, despite that optimization, we can't even provide enough gasoline to keep up with domestic demand. In fact, 1 in 8 gallons of gasoline in this country is imported from European refiners.

If the refiners wanted to switch to optimize for diesel, it would require an investment in the ball park of $500MM-$1bb PER refinery, along with a 4-5 year lead time.

The point is, until that potential switch, diesel supplies (which are already tight globally) would be increasingly strained, driving up prices above gasoline (which they already are in the US most of the time), and hurting diesel's chances against gasoline.

I personally would love to see diesel take off in this country, and there's no question we would be more efficient with it. The question is whether our energy supply chain can keep up with such a switch, and I believe that the answer is no, at least for the med-term.

In all this comment, bio-diesel was largely ignored.

We need an interim method of fueling our transportation. (While waiting on nuclear fusion)

Realistically it comes down to Bio-fuels.

After all that is carbon neutral, solar power.

When the Diesel prices were lower than gasolene prices, I think that owning a Diesel may be better especially in light of its higher mileage.

But, we have to see how much Diesel (% age) comes out of Crude refining.

If all the vehicles in the World convert to Diesel, what will happen to Gasolene.

If we think this way, Nat-gas, Hydrogen and Electricity may be the neutral fuels.

Joseph,

Just about every car on the road has better handling and road feel than nearly any Toyota (save for the now discontinued MR-S, MR2, and Supra). You don't buy a Toyota for handling...you buy them for fuel efficiency and reliability.

If you want to know what a well handling car driving experience is like go try a Mazda 3 or the new Mitsubishi Lancer as they will easily out handle the Jetta TDI.

Increasing the use of diesl is a logical step toward making better use of conventional fuels as they are not going away any time soon. I think we will all continue to use fossil fuels to some extent as long as they are available to extract, and although conventional oil may be ready to peak, overall fossil fuels are still very abundant. Unconventional oil, GTL and CTL, possibly with CCS will pick up the slack to fuel the world economy along with some renewables, but since those are all much more expensive, we will need to be smarter about fuel use. One day diesel or maybe designer fuel vehicles with regen braking will be the rule. I think it is evident that maximizing efficiency for liquid fuel vehicles will happen before battery electric or hydrogen is ever a real option.