What gas are you going to choose for your next car?
When you think of German vehicles, odds are that you're picturing big Mercs and Bimmers speeding on the Autobahn. However, the German market is quite diverse and there's a good supply of alternative fuels to be had. You can get most models powered with gasoline, diesel, natural gas (CNG) or liquified petroleum gas (LPG, also called Autogas). While the debate between the first two choices is quite old, how do you choose between the two latter alternatives? While you can convert a gasoline car to run on LPG, you can't do this with CNG. So which one to choose?
First, let's speak about the cost of fuel itself. According to TÜV Süd, a kilogram of natural gas has the same energy content as 1.5 liters of gasoline. When it comes to costs, the average price of driving with CNG is half of the cost of gasoline. As for LPG, two liters have the same energy as 1 kg of natural gas. This makes LPG about 30 percent more expensive than CNG (and about 35 percent less than gasoline).
There's more after the jump.
[Source: Auto News]
We can't ignore the different cost of the LPG/CNG conversions. Usually, a gasoline-to-LPG conversion costs between €1,800 to €3,500 although some brands are starting to offer them as standard equipment, guaranteed. No CNG conversions are offered and these models usually have a €2,800 to €5,500 surcharge from its gasoline counterparts, although sometimes they cost about the same as a diesel model. A good rule of thumb: if you drive less than 10,000 km per year, stick with a fuel efficient gasoline vehicle.
What about the environmental balance? Both CNG and LPG have the smallest environmental impact among the fossil fuels. Their emissions of CO2 per km are usually 25 percent lower than equivalent gasoline cars, and smog production is about 80 percent less. Particulates, NOx, carbon monoxide and sulfur dioxide emissions are almost zero. Germany is also investing in obtaining biogas from renewable sources, usually waste, which would make CNG more interesting.
Currently, up to 3,000 gas stations in Germany offer LPG pumps, compared to 800 stations offering CNG (although this number is increasing). There are tax advantages to using these fuels, too, although LPG might lose its privileged status in 2018. A taxation scheme based on CO2, which will be introduced in Germany soon, might keep these two fuels as a viable options.
Reader Comments (Page 1 of 1)
paulwesterberg 4:27PM (10/30/2008)
Electric. Gas is for hosers.
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Diffrunt 4:36PM (10/30/2008)
Michelin in (Tweel) wheel motors & suspension, super Cap batts, microturbine generator
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radler63 2:46AM (10/31/2008)
LPG does not save 25% compared to gasoline/petrol
CNG does not save 25% compared to diesel
Please correct.
http://www.greenfleet.info
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jeremie 5:50PM (10/30/2008)
Electric is my next fuel...
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oldraven 8:46PM (10/30/2008)
I've got a propane (LPG) powered '86 C-10. A 350 stroker, that's about as powerful as the most choked malaise factory 350. That's the big trade-off with LPG.
When I first bought the system (everything you see in the photo above, plus the engine) propane was selling for $0.42/L. When we moved home from Alberta in '06, I was paying $0.58, but once we got to Nova Scotia, the pump said $1.02/L, and continued to rise as fast as diesel. I've driven the truck about 40km since then, with most of the full tank I left with still there. It's much more expensive to use, if the price is anywhere near the same as it is for gasoline, since you use so much more fuel to get the same amount of power out of the engine. Your range is less, too, unless you buy a tank so large you have no trunk or cargo space.
But it is very clean. It's hard to tell when you change the oil, since it always stays amber. It also lends itself to high compression, or boosting, with its 111 octane rating. ;) If prices are normal, for this by-product fuel, it is a very cheap way of getting around, which is why I did the install to begin with.
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JamesWB 7:52AM (10/31/2008)
Sounds like you need to tune that engine to run on LPG.
oldraven 9:07AM (10/31/2008)
The engine was rebuilt for propane. I can't tell you what all is involved in that, you'd have to ask my brother. He's the mechanic. He told me the difference at one point, but I just can't remember now.
It's all explained it the blog.
"According to TÜV Süd, a kilogram of natural gas has the same energy content as 1.5 liters of gasoline. When it comes to costs, the average price of driving with CNG is half of the cost of gasoline. As for LPG, two liters have the same energy as 1 kg of natural gas."
That means you need 2L of LPG to every 1.5L of Gasoline, to produce the same amount of energy. 25% more.
JamesWB 6:32AM (11/01/2008)
Yup, I know all that. Ask your brother if he increased the compression ratio to take advantage of the higher octane rating or if he just added hardened valve seats.
oldraven 8:49AM (11/06/2008)
No, it doesn't have domed pistons or anything. The only thing that may affect the CR would be the longer stroke of the 400 crank.
I'm not saying propane is a bad idea, but when it's price is on par with gasoline, it's not economical at all.
MarkR 1:21PM (10/31/2008)
That is not the primary question. However, my next truck must be electric hybrid. Second it will not be Diesel. Third, I'm a Pickens plan supporter, so If the fuel can not be found and refined from the good ole USA, I'd prefer not to be forced to buy it. so I guess that puts me square in the natural gas camp.
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