Car - eco friendly fuel

gromituk

SusanCarter wrote:

The reason LPG is better than petrol (and petrol better than Diesel) is that it has shorter carbon chains so for the amount of energy it provides it produces less carbon dioxide. (I did a degree in chemistry and when someone told me that I didn't believe it so did the calculations based on bond energies etc and found that it was indeed correct.)

I don't think that is the full story though, because you need physics as well as chemistry! I don't know about the LPG situation, but diesel engines consume less fuel than petrol ones - and I presume produce less CO2 - because they have higher compression and thereby can extract more useful energy from the burning of the fuel.

I don't know a lot about Biodiesel but I guess that if it is produced from plants then it is just putting back the carbon dioxide taken out by the plants so is better than releasing it from fossil fuels.

Indeed, in theory, but I have my doubts, because the growing, fertilising, harvesting, refining and transportation of the fuel takes a lot of energy, and I wonder how much of this comes from fossil fuels. It may be a convenient smokescreen like hydrogen cars (where does the hydrogen come from?).

it is good to keep using a car until it "dies" than to replace a perfectly servicable car with a "greener" one.

I agree. The thing we need to do is change our driving habits. I'm sure, if the original poster put her mind to it, she could reduce her environmental impact in some way. She needs to take her children to school - but are there really no other children in the same locality who go to the same school? Lift-share and the school runs are cut in half at a stroke. Does she have the kind of job which allows her to work from home occasionally? How about a car pool? We jealously guard the ultimate convenience of our own transport all the time; this mindset is going to have to change.

I think it had a fuel consumption of around 8 m.p.g. but he said that because it was produced in Los Angeles at a time when there was a lot of pollution problems there, they had the strictest laws on emmissions in the world so it has huge catalytic converters and other stuff so although it uses tonnes of fuels it produces hardly any emissions.

Just in case someone gets confused by the language there: emissions include CO2, and if you consume more fuel you will produce more CO2. Fewer other things, yes, but CO2 is what is really affecting the climate, and fuel consumption is what is really going to cause us all these problems with energy supplies.

I imagine this law was brought in before it was realised what global problems CO2 emissions are causing, as a means to solve a local problem (smog). As a global problem-solver it is counterproductive.

Dan29

A quick search of the Auto Trader website reveals that you can get a Toyota Prius for under £5,000. I believe these are completely free of emissions if you keep under 30mph?

Beverley

Is a Prius one of those cars that runs on petrol sometimes and electric at others? - it's a bit vague but I recall an ad that talked about a car that ran on 2 different fuels depending on speed.

Beverley

Dan29 wrote:

A quick search of the Auto Trader website reveals that you can get a Toyota Prius for under £5,000. I believe these are completely free of emissions if you keep under 30mph?

Dan29

Yep it's got a petrol engine which charges the batteries for the electric motors, so I'm pretty sure you're only running on petrol at over 30mph - around town it's all electric, but without the inconvenience of having to plug it in at night.

There's info about it on the Toyota website although for £5,000 you'd be getting an old shape one - I believe the technology's the same though, just a different body shape.

Beverley

Hmm the things you learn on here

I wonder - is only diesel engines that can run on biodiesel or can unleaded engines do it too?

My thinking is - is it possible to convert a Prius to run on biodiesel so it runs on electric round town and biodiesel at higher speeds - or am I totally off the wall?

Beverley

Dan29 wrote:

Yep it's got a petrol engine which charges the batteries for the electric motors, so I'm pretty sure you're only running on petrol at over 30mph - around town it's all electric, but without the inconvenience of having to plug it in at night.

There's info about it on the Toyota website although for £5,000 you'd be getting an old shape one - I believe the technology's the same though, just a different body shape.

Dan29

I'm pretty sure it's only diesel engines that can be converted to biodiesel.

Beverley

Dan29 wrote:

I'm pretty sure it's only diesel engines that can be converted to biodiesel.

Bummer - though it certainly sounds as if the Prius is worth a look for me - thanks very much

gromituk

Dan29 wrote:

A quick search of the Auto Trader website reveals that you can get a Toyota Prius for under £5,000. I believe these are completely free of emissions if you keep under 30mph?

No, not really - that would be impossible, because you would have a perpetual motion machine! These cars do not charge up from the mains - all their energy input comes from petrol. They contain a small battery to enable them to have better acceleration for a given size petrol engine, and to allow the engine to run at its most efficient speed range more of the time. But this battery has a small capacity, so whatever speed you drive, the petrol engine will still need to come on from time to time to charge the battery.

Ride a bicycle instead.

save-a-lot

Hi

For £5k my brother has a Shogun with a lpg conversion where the tank is underneath and not in the boot, having a dual tank 20% petrol/80% lpg. The car drives about a mile after starting on petrol then switches over to gas. The running costs are small car prices. Best bet is to get a ready converted 4x4 in my opinion, there are plenty of them around. Or try and find a factory fitted Vauxhall Astra, they were sold ready converted from new and they have been in existance for a long time now, just looked on Autotrader and the dual fuel Astra's can be picked up from around £2600 for a 1999 T reg. There are a few £4000 examples with reasonable mileage. Worth considering.

Beverley

gromituk wrote:

I'm sure, if the original poster put her mind to it, she could reduce her environmental impact in some way. She needs to take her children to school - but are there really no other children in the same locality who go to the same school? Lift-share and the school runs are cut in half at a stroke. Does she have the kind of job which allows her to work from home occasionally? How about a car pool?

I live in a locality where I do not want my children to go to school - hence I go to the effort of sending them to school in an adjoining area. Other children in my area do not attend the same school - when one did, I and the other mum took it in turns of course.

I work in a school - try as I might, I cannot see the head allowing the pupils to come to my home just so that I can save the environment.

Unfortunately the school where I currently work is in another town some 18 miles away - it simply isn't feasible to do as you suggest as others aren't interested.

Feeling defensive here.