running costs maths... lpg vs diesel, v6 vs 2.1td

[Homer]

its amazing isn't it. There's no real ensentive from the government to go for either bio or LPG, yet it supposed to be much better for the enviroment?

LPG only really benefits the local area through cleaner exhaust fumes, it doesn't do all that much for CO2 emissions.

Bio Diesel has a huge drawback in that it needs vast amounts of arable land to grow the crops to produce the biodiesel. At the moment this means chopping down the rain forest.

At the moment the best engine for the global environment is a modern diesel running on regular diesel. Electric just moves the pollution elsewhere and hybrid technology just isn't there yet.

[caveman_si]

LPG only really benefits the local area through cleaner exhaust fumes, it doesn't do all that much for CO2 emissions.

Bio Diesel has a huge drawback in that it needs vast amounts of arable land to grow the crops to produce the biodiesel. At the moment this means chopping down the rain forest.

True lpg doesnt have the smallest CO2 footprint out there.

Biodiesel does need space to grow yes. Depending on which type of base plant you use depends on how much. As for cutting down rainforest this only happens if people buy palm oil based bio or palm oil based anything. BTW palm oil is probably in half the daily products you use in your house from food to cleaners.
If you buy rapeseed based bio then it will most likely have been grown in europe and last time no rainforest was touched.

Personally i would love to see more research into growing it in vats/lakes of alge. There is some research going on in newzealand along those line using sewerplant output so it is multipurpose and alot cleaner on many levels.

[deian]

sewer plant? and clean? lol

[Stewart(oily)]

Currently much of the small scale biodiesel production (at least from my supplier) is from waste oil so it has already done its job cooking turkey twizzlers for the county`s children, as it is produced from a renewable resource it is carbon neutral, biodiesel also produces far less particulate "visible smoke" (my MOT tester asked whether the engine was running ) LPG is still a fossil fuel and the concensus seems to be that converted vehicles burn more of the stuff, ie fewer MPG, granted the emissions are cleaner but someone running a V8 on the stuff and getting around 20 MPG can hardly claim to be an environmental champion compared to a 50 MPG diesel.
Stewart

[reblack68]

I'm pretty sure our local power station runs, at least partly, on poo briquettes.

[Stewart(oily)]

I have seen a landfill catching methane gas and running a one megawatt caterpillar generator on it, power to the grid, they were talking about putting a second one in, where theres muck theres brass.
Stewart

[deian]

if only everybody was as creative as that!

[BonceChops]

It is how they produce the bio diesel that is not very green.

One of the products used in the transesterfication process is methanol. Where does most of our methanol come from? Yes you guessed it natural gas

There are other ways to make bio diesel but most of it is currently made using methanol.

[Stewart(oily)]

Agreed methanol is used in the manufacture of biodiesel but it is a very small percentage , up to a maximum of around 4% IIRC
Stewart

[BonceChops]

It's can be as high as 25% methanol if it is used oil that is being converted. Some of the methanol can be reclaimed after use but I suspect most small produces don't because of the expense and safety issues.

Bio diesel can be produced using ethanol which is in turn made from fermenting corn.

[Stewart(oily)]

I have a glass of fermented ethanol in front of me right now
Stewart

[sooty]

It may not be relevent, but I did some sums for LPG or TD.

Against the mileage I do per year of approx 12k and suprising although LPG is approx. 40p/ltr against diesel at approx. 91p/ltr. The TD works out alot cheaper due to its high MPG and depending what engine size you might get the Road fund license is cheaper too over a petrol variant of the same performance.

[deian]

thanks for getting back on subject sooty, i hear your words, the xm 3.0 v6 24v is a rare car and has double the power of my xantia, and half the mileage, having only 108k at K reg, thats quite low.

(don't get me wrong here, i have made my mind up) but i will still ask the question just to get an opinion: whether i sell my 1998, Xantia 2.1td exclusive with 201k miles and buy a 1992 XM 3.0i V6 24v with 108k miles for the same price as i sell the xantia (hopefully a grand).

[KP]

Thats quite true sooty but it depends on if you want a diesel or petrol in first place or if you want cheap running

I had a Xantia LX td running on veg and nothing beat it, 615miles to £24 of veg compared to 190miles on LPG in the coupe which is about 36litres in the tank as well

But then again then Xantia takes shed loads of kit in it and has a very good ride upto about 80ish but at that speed and over the coupe beats it hands down on a run(unless you come to the highly maintained sections of our road network!) and still returns the same MPG there abouts

[genius149]

The problem is you cant get free congestion it has to have been covnerted by the manufacturer or be on the database thing which aint cheap to do.

No reduction in tax either for people who convert after their car was made either im afraid.

I don't drive through London so have never had to worry about the database problem.

I do save a tenner a year on tax - not much, but it's just under half a tank of LPG so it's about 100-120 free miles a year.