I think it looks kind of like an old Porsche. Nice!

I wonder if it's coming to the US

It doesn't appear to have airbags or bumpers that would meet US spec. Adding the necessary equipment safety equipment would increase weight and cost and decrease efficiency. On the other hand, I think you could convert most any gasoline 4 cylinder roadster to CNG with similar results, for a lot less than $70k. You can pick up a decent 1.6L Miata (MX-5) for about $3000.

Why CNG when LPG is just as clean, runs more efficiently in vehicles, has better filling infrastructure, is cheaper, weighs less in a vehicle, is cheaper to run and purchase, and is a clean byproduct of CNG production?

That's a good question, Peter. I wonder if there's any technical reason...

Biogas, or regular gas, the fueling is a red herring. In fact, the only thing different about this car is the fuel. It still requires massive expenditures in roading, still contributes to annual road casualties, still creates distances for all that only the automobile can close for a few.

Perhaps more subtly, and dangerously, the Cevennes promotes the myth of the open road, the constant frontier. If we don't like the cities we've created, we can just leave. TreeHugger needs to be more critical of this type of technofetish 'innovation' that defers responsibility and seeks to prolong a status quo that is both problematic and temporary historically.

@Luke

While I agree with you, I don't think that's a practical fight to pick. Society and its infrastructure are already too far down the road (pun intended I guess) to move completely away from automotive biased transit.

About the car: never underestimate methane. Its nature's cleanest and most efficient method of energy storage. We, as humans, can source it from dozens of places. Even if we were to continue to use "fossil" fuels, there is no end in near sight for methane. Natural gas hydrate deposits are estimated to be larger (in energy) than all of the coal, oil, natural gas, and uranium we've ever had COMBINED.

Also, note that the compression ratio is "only" 11.1:1. That's really too low to take full advantage of NG's octane of 130. Room for improvement...

LPG is not a byproduct of CNG production, but of petrol destillery. Whereas the mix of methangas use for vehicles in Europe is containing biogas, for LPG there is no bio-version available.

Concerning compression ratio: If operating with supercharging, the compr.ratio of any engine is lower than for an engine without turbo. The 11:1 together with an elevated bioost presure is gaining the max. advantage of the 130octane-fuel CNG.

best regards

Re: Tschopp

According to 2000 statistics from the National Energy Board of Canada, 85.4% of propane production was at natural gas plants. I am not sure what the production is in other countries, but I'm sure the data is available.

As for your point about bio-versions, etc. propane is designated (as well as CNG) as a clean fuel by the United States’ Environmental Protection Agency, among others.

Concerning compression ratios; I'm sorry I can't really go toe-to-toe with you on that as I don't know that kinda thing, but I do know that with new fuel sequential injection propane systems vehicle efficiency is within 3-5% of gasoline efficiencies while significantly reducing emission across the board (smog, particulate matter, CO, CO2, etc). Furthermore, on a more practical level, the density (lb/gal) of propane is 4 times more than CNG, allowing more fuel in a smaller space (allowing practical vehicle range). This lbs/gal problem is further exacerbated in our next miracle fuel, hydrogen, where density is a major issue when applied to tank size and pressures required for regular use.

Basically, I haven't found a major flaw for the use of propane as an alternative vehicle fuel; when vehicle use is absolutely necessary ;).