Well the New York Times is a pretty respected paper. Here’s what they have to say:

When Europeans think of diesel, they think of the very cars — small and smart — that half of them are driving now. When Americans think of diesel, they think of semis and buses and pickups and, perhaps, one of the lumbering Oldsmobiles that did so much in the 1980’s to poison the promise of diesel technology here. Europeans and Americans differ in almost nothing more than they differ in diesel, including different emissions standards and different fuel quality. But in the next few years, as the rules on air quality tighten, Americans need a diesel engine that can meet the stricter standards.

Diesel engines offer more torque and greater fuel efficiency than gasoline engines, and they emit less carbon dioxide, a greenhouse gas. The drawback is that they also emit more particulate matter and nitrogen oxide, which contributes to smog. Honda recently unveiled a new engine that solves that problem, using a special catalytic converter that turns harmful nitrogen oxide into simple nitrogen. Honda plans to introduce this engine in the United States in 2009, which just might give us time to improve the poor quality fuel that keeps diesels here from being as clean and as popular as they could be.

It’s always tempting to hope for a futuristic solution — like the new fuel-cell car Honda also demonstrated the other day — for the very immediate problems of auto emissions and fuel efficiency. But the answer is going to lie in a mix of vehicles — hybrid cars, more efficient gasoline engines, and highly improved diesels. The answer is also going to come from recognizing that strict limits on emissions and mileage penalize only those companies that are too sluggish to compete.

Source: newyorktimes.com

In Kanagawa University in Japan, researchers have developed Super Emulsion Fuel. Super Emusion Fuel is an emulsified diesel fuel that lowers emissions while boosting fuel economy 10-15%.

Emulsified diesel fuel is a mixture of diesel fuel with water and emulsifying and stabilizing additives. The practice of adding water to diesel dates back to the early 1900s, and there are hundreds of different patented implementations. Depending on the application, the water content may vary from 8%-35%, with a typical 13% water formulation for diesel engine use.

Whereas the old method of emulsification used surfactants to get the water fuel mix, the new process uses a three phase emulsification process. The new process exploits the weak molecular attraction between things that have a high affinity (absorbing or dissolving) for water based nano-particles. Instead of having a specific surfactant for each type of oil, this process can be used for any.

All this means is a better boom in the cylinder by making the fuel disperse better and in smaller particles. Also by giving those particles more surface area to contact the air.

Terms:
Surfactant - a substance that when dissolved in a liquid solution, reduces its surface tension.
Emulsification - a suspension of small globules of one liquid with which the first will not mix.

BMW is now touting the world’s most powerful straight-six diesel (I’m sure they just forgot to add in “in a car” or maybe “in the 3.0L and lower class”). Their new six delivers 286hp (210kW) and 427ft-lb (580Nm)of torque at 1,750rpms, which will be going in the 335d. BMW will also have a 325d pumping out 197hp (145kW) and 295ft-lb (400Nm) of torque at only 1,300rpms.

The BMW 335d will be using their Variable Twin Turbo Technology (VTT) introduced in the 2004 535d. It’ll also shed weight by using an all-aluminum crankcase to drop 44lbs. The new fuel injection system will use compact piezo-injectors that will be able to inject fuel at up to 1,600 bar, or for most of us that means 23,206psi, which helps performance. The injections system allows for up to 5 injection processes in each operating cycle. The angle of the jet needle and injection volume is all controlled to provide the best performance and fuel economy. The 335d should get a combined 31mpg, while the 325d should reach a combined 37mpg. Combine that economy with a 0-63mph time of only 6.1 seconds for the 335d, and 7.4 seconds for the 325d and you have the best of both worlds.

(more…)