To assist their gas engines, Nissan has developed e-4WD, or electric four wheel, which uses electric motors but has no batteries. Is this a hybrid? Yeah. Think of it as a mild series or serial hybrid, which is a kind of hybrid that uses a generator instead of a battery to power the electric motors. Wait a minute, you might say: aren't four wheel drives less efficient than two wheel drive cars? Yes but e-4WD is very light and compact because it's electric.

Okay, so how long before the fuel savings pay for the added hardware? It's not that clear because e-4WD is only used on a few specialized vehicles like Nissan's March (see video below the fold). Estimating exactly how much a hybrid improves fuel efficiency is not a trivial task but as more vehicles use e-4WD, it should become clearer. Also, the system's primary goal is not improving efficiency but horsepower (Torque: 109 pound-feet, Horsepower: 90 hp). Performance ... hybrids? "That's an oxymoron" you might say, laughing, before you remember what Lexus is up to.

While the idea is rejected by most automakers Nissan is planning to make performance hybrids. Greens like the growl of a good engine and watching a guy get smoked in a race, even if the EPA thinks it's a contradiction. Soon, when talking about a hybrid, you won't just ask how much more fuel efficient is it but how much more POWER does it offer. The lack of a battery in the e-4WD should keep the costs low as well.

Related:

• Nissan confirms the "Cube," a 37 MPG, hybrid, Scion-look-a-like, is coming to the US

[Source: Nissan]

Click on the image for a gallery of high-res images of the 2007 Mercedes-Benz E320 Bluetec.

Writing for the Los Angeles Times, Dan Neil has a good piece about the California Air Resources Board adopting the EPA's Tier II, Bin 5 emission standard two years before most of the U.S. leaving the 2007 Mercedes-Benz E320 Bluetec as out of reach for Californians. Neil points out that the new E320 Bluetec does meet the Bin 8 emissions standard and gets 45 percent(!) better fuel economy than the equivalent petrol-powered E350.

Bluetec of course is Mercedes-Benz's branding for their clean diesel technology which sees the E320 Bluetec equipped with a NOx adsorber-catalyst, exhaust gas recirculation and a particular filter. Like your average modern oil burner, the off-the-mark times and power ratings aren't all that noteworthy, but the torque is massive. Neil describes the E320's pull well, "[it] has torque like a nuclear attack sub."

As I described in my recent Volkswagen Passat TDI review, all that torque results in amazing overtaking ability, "Even while driving up a reasonable gradient doing 100 km/h with the engine ticking over at 1,500 revs in sixth, there is torque on tap to blow past other cars without the Direct Shift Gearbox (DSG) even needing to switch down if you bury your foot."

Neil describes a similar sensation in the E320, "In the passing lane, this inoffensive burgher of the interstate pulls like a BMW M3."

Analysis: The only problem with buying a huge saloon with a clean diesel engine and great fuel economy is that you probably should have bought a smaller car anyway. Switching to diesel vehicles to maintain an unsustainable love affair with big vehicles is false economy.



Click here to watch Neil eat an E320-toasted bagel.

Related:

• In the AutoblogGreen Garage: 2007 Volkswagen Passat TDI
• Green Car Journal names its favorite 2007 models
• Camry Hybrid named 2007 Canadian Car of the Year

[Source: LA Times]

Siemens VDO has announced that for the first time an engine equipped with piezo direct injection gasoline (DIG) technology has featured in Ward's 10 Best Engine List of 2007. The 300 hp / 224 kW BMW 335i Twin Turbo 3-liter engine, which features Siemens VDO DIG technology, was unveiled at the Geneva Auto Show last year.

The piezo technology, in conjunction with advanced engine management systems, is credited for delivering higher torque and improved vehicle fuel economy. Direct injection fuel delivery, which is widely used in diesel engines, injects gasoline directly into the engine's combustion chamber, enabling the vehicle to start with less fuel, while simultaneously improving vehicle drivibility and emissions.

Related:

• Ward's Auto releases annual 10 Best Engines list
• Ballard selling electric drive operations to Siemens VDO
• Suppliers pushing competing diesel injector types to clean up diesels

[Source: Siemens VDO]