Thread: What's more environmentally friendly, a Disco/Defender V8 or Diesel?

The most environmentally friendly car would the early series cars that are still on the road

the longer are car lives the more environmentally friendly IMO

Originally Posted by dullbird

The most environmentally friendly car would the early series cars that are still on the road

the longer are car lives the more environmentally friendly IMO

Quite true Lou, the exhaust emmisions are relatively negligable. By far the most polloution is generated in the manufacture and disposal of all goods.

Before you can settle the question you have to decide what you mean by environmentally friendly! Then you have to decide what period of use you are going to consider, then specify what happens to the vehicle after it ceases to be used. Then you have to specify what mileage it will do per year, and how it will be driven.

John

Originally Posted by JDNSW

Before you can settle the question you have to decide what you mean by environmentally friendly! Then you have to decide what period of use you are going to consider, then specify what happens to the vehicle after it ceases to be used. Then you have to specify what mileage it will do per year, and how it will be driven.

John

And select the parameters according to the result you want.

Originally Posted by dullbird

The most environmentally friendly car would the early series cars that are still on the road

the longer are car lives the more environmentally friendly IMO

I have a 53 Willys jeep as my daily driver, it weighs a ton.

Originally Posted by V8Ian

Quite true Lou, the exhaust emmisions are relatively negligable. By far the most polloution is generated in the manufacture and disposal of all goods.

But both cars would cost(environmentally)about the same, as only engines are different.
Hence why I said ..............."to drive", sorry if I didn't word that better.

Originally Posted by JDNSW

Before you can settle the question you have to decide what you mean by environmentally friendly! Then you have to decide what period of use you are going to consider, then specify what happens to the vehicle after it ceases to be used. Then you have to specify what mileage it will do per year, and how it will be driven.

John

I think how it will be driven(ie loads, lead foot, stop starts, etc)is the main argument. I guess time frame is relivant, as engine life differs.

Originally Posted by V8Ian

And select the parameters according to the result you want.

LOL, yeah, seems that way, especially with most of the stuff I've read so far.
So in short, do you guys not know? Or will the variables make such a difference?

I have a table here that I got off the net through an email that deals with total cost,, "Dust to Dust".
This equates everything from the drawing board, processing, manufacture, to the tip/recycling end of things.
This came about to shut some people up about how good the Prius was supposed to be.
In 2005-2006, some 322 cars were anylised, and the Range Rover Sport, and Discovery come in below the Prius,, An FJ Cruiser is just below them in cost,, but the Land Cruiser is well above total cost,

This reprt was telling of the fact that the Prius, although cheap to run, was far more expensive overall to even the Hummer. It pointed out facts like the substance used to make the special batteries was mined in the U.S. and then shipped (by boat) to Europe somewhere, processed, and then shipped back to the U.S..
One of the biggest problems is the 50sq miles around the processing site, which is now void of any life forms due to the acid rain, so much so, that it is used by NASA and the like, to train their guys for something,,(not sure what).

So, as has been said by Dullbird and V8Ian, the longer a car can run for, the cheaper it is in the longrun. This is one of the plights with the Prius,, "short life span"....
So all these things should be taken into account when discussing your topic,,

Originally Posted by 3 Sisters

So in short, do you guys not know? Or will the variables make such a difference?

The only difference between the two is the engine, and the differences between a V8 on LPG and a diesel as far as driving emissions go is fairly small (and could go either way) - the higher compression of the diesel plus the recovery of exhaust energy from the turbocharger means a higher Carnot cycle efficiency compared to the V8, and this will probably about cancell out the difference in carbon intensity of the two fuels.

This leaves other factors to consider. One of these is that the V8 will probably encourage more enthusiastic and hence fuel wasting driving. But against that, the diesel weighs a little more - but it does not have to carry round as much fuel on average or the LPG tank.

The V8 has a lot larger proportion of aluminium in its construction, and this is much more energy intensive than steel or cast iron, but the effect of this on overall lifetime emissions is very dependent not only on engine life, but on what happens to the engine after it is scrapped. And this is also affected by things like how repairable is the engine, which will affect the service life of the engine, and hence very likely the vehicle. And while the design and manufacturing emissions for a vehicle are fixed once it is sold, the amount per kilometre (the usual measure) is obviously very dependent on the life of the vehicle. In a similar manner, long lasting designs "owe" less per unit for design and development emissions, so, for example, the long lived V8 almost certainly represents lower emissions per engine than, say, the relatively short lived TD5.

John

Originally Posted by JDNSW

The only difference between the two is the engine, and the differences between a V8 on LPG and a diesel as far as driving emissions go is fairly small (and could go either way) - the higher compression of the diesel plus the recovery of exhaust energy from the turbocharger means a higher Carnot cycle efficiency compared to the V8, and this will probably about cancell out the difference in carbon intensity of the two fuels.

This leaves other factors to consider. One of these is that the V8 will probably encourage more enthusiastic and hence fuel wasting driving. But against that, the diesel weighs a little more - but it does not have to carry round as much fuel on average or the LPG tank.

The V8 has a lot larger proportion of aluminium in its construction, and this is much more energy intensive than steel or cast iron, but the effect of this on overall lifetime emissions is very dependent not only on engine life, but on what happens to the engine after it is scrapped. And this is also affected by things like how repairable is the engine, which will affect the service life of the engine, and hence very likely the vehicle. And while the design and manufacturing emissions for a vehicle are fixed once it is sold, the amount per kilometre (the usual measure) is obviously very dependent on the life of the vehicle. In a similar manner, long lasting designs "owe" less per unit for design and development emissions, so, for example, the long lived V8 almost certainly represents lower emissions per engine than, say, the relatively short lived TD5.

John

Yes, this is the right approach to take. All else being equal, which is the most environmentally friendly ...

John makes good observations here. I would only add two more:

Diesels require more servicing than petrol motors. This can have a greater impact on the environment - more oil, filters, etc, are used.

The particulate matter in diesel emissions is quite carcinogenic, more toxic than the emissions of an LPG powered engine. So even if the emissions are about the same, the effect of the emissions on people are different.


Willem