LPG vs Biofuels: Cleaner fuel but more CO2
Most of our readers might not be familiar with LPG (liquefied petroleum gas) but it's a fuel that is very hot in countries like Belgium, Germany, Italy, France and Australia. LPG is a mixture of hydrocarbon gases (propane and/or butane) that is liquefied and then used as a fuel. It is non-toxic and non-corrosive, and it burns cleaner than gasoline or diesel and is much more free of particulates when compared to the latter. However, it's got a lower energy density, with a lower mpg. Still, since many governments impose lower taxes on LPG than other fuels, using LPG is still usually quite cost effective.
I found an article on the French site Moteur Nature that states that low taxes on LPG is actually counterproductive. The reason? The cost of CO2 per km becomes cheaper, and therefore more pollution hits the air. Since virtually all gasoline cars can be converted to run on LPG, Moteur Nature says this is an open door for people to keep those large SUVs instead of downsizing (I know of a couple such cases among my acquaintances). Here is a good example:
Citroën C2 1.1, a subcompact with a small gasoline engine, pollutes 141 g of CO2 per km. It burns 5.8 l/km (40.5 mpg). At France's price of gasoline, 1.35 EUR/liter (that's like 7.8 USD/gallon), we have to spend 78.29 EUR to run 1000 km and we'll produce 141 kg of CO2.
Then, take a more polluting car: Ford C-Max 2.0, a compact people mover. It pollutes 169 g of CO2 per km. It burns 10.5 l/km (22 mpg). At France's price of LPG, 0.75 EUR/liter (that's like 4.4 USD/gallon), we'll spend 78.29 EUR to run 1000 km while producing 169 kg of CO2.
The conclusion is that LPG is not a good solution if we want to reduce CO2 emissions. Calculating for the complete lifespan of a car (about 150,000 km / 90,000 miles), a car running on LPG will produce 4.2 tons of CO2. Meanwhile, Germany just reduced government support for biofuels but has kept tax breaks for LPG. Moteur Nature is against that policy.
[Source: Moteur Nature]
Reader Comments (Page 1 of 1)
Blaine Decker 12:18AM (3/11/2008)
Did they bother to test the same vehicle, or just one that is worse on performance and emissions?
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rgseidl 4:59AM (3/11/2008)
The comparison is ludicrous, the C2 is a markedly smaller vehicle. In this example, it is also equipped with a 1.1L engine vs. the 2.0L in the C-Max. Apples and oranges, ABG! Your conclusions are meaningless.
Btw: in Germany, the C-Max is also available in a CNG version that comes in at 4.4kg/100km = 158gCO2/km (on NG). Price is around EUR 0.90/kg vs. EUR 0.70/L for LPG. For 1000km, you'll spend around EUR 40 on CNG, i.e. roughly half as much as with a gasoline model. The principal reason is that Germany has decided to give CNG a tax break through 2018.
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Matt 8:10AM (3/11/2008)
I imagine this gent would really hate all the LPG Range Rovers on our roads in the UK. :-D
I for one love it. It's cleaner, cheaper by half, and easy to convert to. I've even heard of RX-8s on it (yeah, rotary engine on LPG = awesome). Next car for me will be LPG converted. Let's just hope the network of distributors expands.
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psarhjinian 10:20AM (3/11/2008)
Biopropane would be a good thing. You get the lack of (relatively) unlocked carbon inherent in ethanol or biodiesel, but with fewer emissions.
Hybrid LPG would be an even better thing.
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psarhjinian 10:30AM (3/11/2008)
So, let me get this straight: a tax benefit to encourage LPG is bad, because it means people will buy a bigger car with comparatively poor fuel economy.
The problem isn't LPG, it's cheap fuel. Encouraging LPG (over diesel or gasoline) is a good thing. It's not perfect, but I'd rather have people burning it than utter nastiness that is diesel.
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