The CNG Astra is good

Will these diesel cars be US compliant?

I wouldn't assume GM is bring us the diesel version until GM actually says so. Between emissions laws and demand (not to mention GM's loud campaign for E85) it may not happen.

What I find most interesting is that GM is making the big introduction at the Chicago Auto Show. Typically the North American International Auto Show in Detroit in January would be the location for big announcements like this. So this seems like a bad sign for the Detroit NAIAS...

John -

note that only the Astra Caravan wagon is currently available with a CNG option in certain European countries. Special versions already exist for police, taxi and other fleet operators, who would likely be the only viable customers for the technology in the US right now. There are no public CNG filling stations there yet.

Dave -

afaik, GM has not announced any intention to offer T2B5 diesels in Saturn passenger cars. Look for them to expand heir Green Line hybrid option and bide their time while others spend their marketing budgets on making diesel acceptable to a skeptical US public. Remember, the folks who read GCC are far from a representative cross-section of the population.

If clean diesel does catch on, Saturn could probably make a diesel option available in fairly short order (~2 years). Ironically, the biggest bottleneck appears to be getting a slot in the calendars of EPA and CARB for vehicle certification.

My educated guess is that GM Powertrain has active but undisclosed projects executing technical evaluations of various NOx aftertreatment systems as we speak. They likely also have some purchasing guys crunching the numbers to predict at what scale lean-burn NOx mitigation technology will become cheap enough to meet GM's financial targets.

The company would arguably be negligent towards their shareholders if they didn't perform this due diligence, if only because European regulators will likely fall over themselves to match US limits once that becomes technologically and economically feasible (Euro 5's focus on PM is close to a done deal, but Euro 6 already looms on the horizon and could perhaps come sooner than initially planned).

Much the same is true of all other carmakers that have not yet announced any plans to bring T2B5 diesels to the US market.

Note that the original Astra Diesel Hybrid concept car was a mild variant based on an integrated starter-generator and a 42V DC grid. The electric motor was rated at ~20kW. The specially shaped battery was mounted in the space normally used for the spare tire underneath the trunk floor.

The project appears to have been discontinued in favor of the two-mode full hybrid. Either way, GM - like others - appears to have concluded that diesel hybrids are too expensive for mass production at this time. Citroen has limited its efforts to stop-start microhybrid functionality, but even that is delivers 5-10% gain in fuel economy. The snag is that diesels are already quite frugal, so saving 10% doesn't amount to as much in absolute terms.

Rafael -

A researcher at Argonne National Laboratory (ANL) suggests that diesels actually benefit more from hybridization that gasoline engines (at least based on the PNGV diesel-hybrids):

"Comparing with commercial gasoline HEVs, my estimates imply that PNGV diesel HEVs get far better benefit from hybridization, but far less from engine downsizing….”

http://www.transportation.anl.gov/pdfs/TA/89.pdf

That seem counter-intuitive to me, but I'm not an engineer. I'd be interested in your thoughts on this.

Carl -

that particular study looked at diesel hybrids in the context of the PNGV program, which the Bush administration shut down in favor of the hydrogen-centric FreedomCAR project. The original goal of PNGV was a family sedan delivering 80MPG by 2004.

While it is certainly true that pairing a downsized diesel with a mild or full hybrid will improve fuel economy, the cost of the combo is very high. The battery/ultracaps, the power electronics, the electric motor and the integrated hybrid control system all carry hefty price tags on a per-kW basis, compared to ICE technology.

Moreover, the effort (read cost) required to get a small diesel to meet the ultra-strict T2B5 regulations is not significantly lower than for a mid-sized engine. Besides, in the 1.0-1.5L displacement class, a three-cylinder is thermodynamically preferable to a four-banger. Inline threes are quite common in European subcompacts but they do generate more noise and vibration due to free first order moments. Adding a compensation shaft eliminates the cost benefit due to the lower cylinder count.

You're correct in identifying that cost is the problem. The production cost penalty of the coming "clean" diesels is about the same as a gas hybrid (approx $3k each); this would make a diesel hybrid about $6K more expensive than a comperable gasoline small car. Also, considering the PNGV tests: was the gasoline engine a fully optimised one (Atkins cycle)? A fully optimised (for hybrid use) Atkins cycle substantially reduces the inherent efficiency gain of a diesel from a more typical 30% to perhaps in the 10-15% range. This small proportional gain would come at too great a price; I don't think we'll see (clean)diesel hybrids for the foreseeable future.

i wonder what the "natural" (untaxed, unsubsidized) costs of bioethanol, biobutanol, biodiesel, and any other bio-fuels are.

also their net energy and CO2 outputs.

and other environmental impacts involved production and use. (biodiesel may be great, so long as it doesn't increase our smog and lung cancer problems)

add those things up and you could really compare diesel, spark, and hybrid versions of each and come up with a useful answer.

GM is not going to offer E85 on smaller vehicles.
They will offer only on larger vehicles, so that people are forced to buy those.

But Brazilian company is going to sell a kit that will make gasolene vehicle run on E85. Untimately thats going to win the market.

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Somebody said there are no public CNG stations in the US. There are in fact 786. This URL has details of stations for many alternate fuels:

http://www.eere.energy.gov/afdc/fuels/stations.html