AutoblogGreen

What about the emissions generated from compressing the air in the first place?
Doesn't look like they accounted for that.
Kind of like the hydrogen cars that don't account for energy used to make the hydrogen in the first place.

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There are so many exciting cars supposedly coming to the US in the '09-'10 timeframe. Here's hoping a few actually get here by then and aren't terrible, as that's right around when I plan to replace my aging '93 civic, which still gets better mileage than most modern US cars, with the exception of the Prius.

Otherwise, I'll probably just end up w/a Honda Fit

- Red - http://unstarved.com

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"What about the emissions generated from compressing the air in the first place?"

Tht's why it's the equivelant of 106 mpg and not infinity mpg.

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1) 848 miles only comes from the "range extender". Basically, they burn fuel to heat up the air as it enters the cylinders. Which is less efficient, BTW, than just burning the fuel in a gasoline engine. Air cars typically have less range on compressed air than electrics have on batteries because while the mass density is decent on compressed air, the space density is horrible.

2) The emissions they cite are only from the fuel burned in the car, not counting the energy in the air tanks. 0.158 lbs/mile is not "negligable"; that's 110g/km, not that much better than a good diesel, yet this is *only the emissions from the burned fuel*. And they're only talking 35 mph, which has 1/4 the wind drag of 70mph. As for the carbon emitted from filling your tanks, you still need to account for the power plant, transmission, and compressor losses.

3) Modern power plants are ~40-50% efficient (older can be as low as 30%, future perhaps as high as 60%). Transmission in the US is a touch over 92% efficient. Onboard and "home" compressors are typically 10-15% efficient. Big industrial regenerative compressors can only reach up to 60% efficient. In short: use a *non-boosted* air car powered by a home compressor if you want to *destroy* the environment, and one from an industrial compressor if you want to make no difference to the environment. Use a boosted air car if you want to destroy the environment, period.

4) Performance in air cars drops as you burn through the tank, meaning more inefficient fuel burning.

5) I'd trust a Tata Motors car about as much as I'd trust a Chery:

http://www.youtube.com/watch?v=5kQGAK550LE

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tankd0g, I think Karkus is right. The 106mpg is from fuel burned to heat up the air tank:

"The projected CO2 emissions should be negligible (0.158 lbs/mile) when cruising at over 35 mph (the car uses small amounts of fossil fuel to get air in a heating chamber up to temperature at those speeds)"

The overall inefficiency of storing energy in compressed air will still be a problem in the "well-to-wheels" analysis. Maybe they can sell PV-array powered air compressors for our garages.

Inefficiency notwithstanding, getting 850 miles range out of a tank of air is impressive. I wonder what the compression is.

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GoodCheer: Without the fuel burning range extender, the CityCat's range is only 125 miles and its top speed is 68mph:

http://vechicles-that-rocks.blogspot.com/2007/05/indian-city-cat-car-that-can-run-125.html

They're pushing the tech about as far as it can go, unfortunately, barring a dramatic materials breakthrough. There's not really any more room for more tankage, and the tanks are already very high pressure.

Air cars are just a really bad idea.

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I'll believe this when I see it on the streets of America. The sheer number of vaporware announcements is reaching fever pitch.

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Have 3DStudioMax will travel, apparently.

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Is anyone keeping track of how many green cars are coming out in 2010? Off the top of my head, I count:

Air car
Fisker Karma
Chevy Volt
Plug in Prius
Aptera

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Does an air car that does not exist the equivalent of vaporware?

And does an air car really need air bags ;-)

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aptera is not a car!

it is a 2-seat, 3-wheeler which is not required to undergo crash tests, no better than a NEV

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Will the US-based Oil giants allow this? Highly doubt it...

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Why is it I never hear the alt-fuel or alt-transportation nay-sayers complaining about the lack of well-to-wheels calculations on the stickers of gas powered cars?

How much potable water, electricity, fossil fuel, etc does it take to find a good site, drill an oil well, create the machinery to extract the oil, create pipelines to transport the oil, [wage wars to protect the site], build refineries, refine the oil into fuels, and transport those fuels to the pump?

How far would your MPG fall on a gas-burning car if you had to include those numbers? how much would the pollution indexes rise?

Compressed air might not be as great an idea as electricity, but like electricity it doesn't HAVE to be produced with fossil fuels. An electric motor can compress air just as well as (if not better than) a gas powered engine. And we ALL know that electric motors are a great way to use renewable energy sources, right?

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Zero Pollution motors also intends to enter the AirCar into the Automotive X Prize:

http://xprizecars.com/2007/12/mdi-inc-and-zero-pollution-mot.php

But as KarenRei says above, I have my doubts that it's actually efficiency enough to meet the "100 miles per gallon equivalent" requirement. It will be interesting to watch at the qualifiers, that's for sure :-)

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This is the fossil fuel/compressed air hybrid, and the "106 mpg" only covers fossil fuel used, not the energy used to compress air. Rather like the plug-in hybrids, the overall efficiency is a bit harder to quantify. I suspect they may be exaggerating the performance specs a bit.

There will likely be several plug-in hybrid and EV models available by the time this reaches market, providing stiff competition. The "Air/fuel hybrid" might be cheaper to buy, but the PHEVs will be more efficient to run, and EVs will be several times more efficient to run.

There will be a market for these, but how big depends on how close the reality comes to the hype, and how many ultra-high pressure air refill stations will be available.

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Air Car coming. How many have they built and sold anywhere yet? US market next year?

Bill: "aptera is not a car!" Correct!, aptera is a vehicle! with 2 passengers, side by side seating, will undergo crash testing, and be way better, with a top speed of 95mph, then a NEV. It really isn't a car, nor a motorcycle.

Wonder if they could air power an aptera.

S

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Without the range extender a range of 125 miles is still as good enough. A price tag of less than $18,000 under cuts the Volt, Aptera and Plug in Prius.

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[quote]Without the range extender a range of 125 miles is still as good enough. A price tag of less than $18,000 under cuts the Volt, Aptera and Plug in Prius.[/quote]

And hurts the environment more than driving a gasoline car (depending on how you charge, potentially a lot more), so why bother?

[quote]it is a 2-seat, 3-wheeler which is not required to undergo crash tests, no better than a NEV[/quote]

They've been working for months with CD-Adapco and ABAQUS conducting simulated crashes, and are in the process of moving to actual crashes. It is designed to meet or exceed all relevant car safety standards.

Just because something isn't "required" doesn't mean it isn't being done.

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Regarding the first comment: With gasoline and diesel, the costs of exploration, drilling, pumping, transport across oceans, refining and further transport are never figured into a vehicle's energy footprint either.

How much CO2 is released per gallon of fuel from the production of crude oil in Saudi Arabian wells to a gas pump in Chicago?

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A lot of conflicting information. On the X-Prizes/MDI site it only claims a 60 mile range. Either way (60 or 125 miles), how do they get to 800-1000 mile range by heating the air with a gasoline heater?

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