What is greener, diesel or petrol?

[Deleted member 2227]

You hear lots abut CO2 with petrol cars and particles from diesel. Which is the most "Green" option?

 

[glojo]

Dunno, but I do know some diesel is red

I suppose the statisticians can have a field day answering your question. The petrol heads will be spouting off one set of figures, whilst the oil burners will use a completely different set, or perhaps the same figures with a different interpretation.

Each to their own and just enjoy the car

Regards,
John

 

[pammy]

You hear lots abut CO2 with petrol cars and particles from diesel. Which is the most "Green" option?

Shanks' Pony but think I'm walking a 50 mile round trip each day!! I think not

What is greener is driving more steadily using smaller engined cars so the fuel we do use goes as far as possible. And no - not doing that either

 

[Benzowner]

From a personal point of view, petrol is best, it does not get slippery when wet, as I found on my bike this morning Probably, with todays modern engines and cats on the exhaust, there is little or no difference between either, but I stand to be corrected. As John said, the numbers will be made to look the same from both sides of the fence so to speak

 

[Satch]

Depends on how you define "Green"!

However:

http://www.eta.co.uk/tools/car-buyers-guide.asp

 

[tacsi]

apparently over in Ireland they have green diesel used in ambulance's etc !

 

[grober]

Many Factors Involved But Some Obvious

Diesel engines are inherently better energy convertors of fossil fuel than petrol due to their greater thermal efficiency. BUT THATS THE SIMPLE EXPLANATION!! the real world picture is very much more complicated.
Heres a real world choice assuming unlimited funds. You want to buy a new Mercedes E class:bannana:
E 220 CDI diesel overall mpg manual gearbox 44.8, 177 g/Kg CO2
E 63 AMG petrol overall mpg auto gearbox 19.8, 341 g/Kg CO2

On paper they are both E class saloons and will safely transport you from A to B but you don't need me to tell you which is the more environmentally friendly car.

 

[Howard]

But which one would be more fun ?

 

[andy_k]

interesting figure I read at the weekend. If cars were limited to a maximum speed of at or around our 70 mph national speed limit they could be made anything up to 50% lighter without sacrificing any rigidity or safety - now think how much fuel that would save? Ooops, Volkswagen and Audi already did with their 3L concept cars and A2 production vehicles trouble is they were expensive to make and nobody bought them.

Let's not kid ourselves, asking which fossil fuel is greener is not really the right question. Which does the least amount of damage? would surely be nearer the mark.


Andy

 

[fuzzer]

surely this would have to be calculated on a total cost of ownership over a certain period.

this includes money and overall environmental cost from cradle to grave.

 

[DieselE]

Diesel engines are inherently better energy convertors of fossil fuel than petrol due to their greater thermal efficiency. BUT THATS THE SIMPLE EXPLANATION!! the real world picture is very much more complicated.
Heres a real world choice assuming unlimited funds. You want to buy a new Mercedes E class:bannana:
E 220 CDI diesel overall mpg manual gearbox 44.8, 177 g/Kg CO2
E 63 AMG petrol overall mpg auto gearbox 19.8, 341 g/Kg CO2

On paper they are both E class saloons and will safely transport you from A to B but you don't need me to tell you which is the more environmentally friendly car.

If you follow the link posted by Satch, the ETA (whatever that stands for) rates the E320CDI considerably more environmentally friendly than the E220CDI Manual, despite a higher CO2 emission (194 g/Kg). The version they choose is the straight six in EU4 state, yet the EU3 version has lower CO2 emissions (183 g/Kg) on 16" wheels.

To me it confirms the old saying, "there are lies, damn lies and statistics".

 

[BenzComander]

interesting figure I read at the weekend. If cars were limited to a maximum speed of at or around our 70 mph national speed limit they could be made anything up to 50% lighter without sacrificing any rigidity or safety - now think how much fuel that would save? Ooops, Volkswagen and Audi already did with their 3L concept cars and A2 production vehicles trouble is they were expensive to make and nobody bought them.

Let's not kid ourselves, asking which fossil fuel is greener is not really the right question. Which does the least amount of damage? would surely be nearer the mark.


Andy

Agree Andy, I would like to see some figures for comparing the environmental damage caused by producing new cars, against running a recent model for longer. Imagine if all new cars bought were kept for six years as opposed to the more regular three??

As I have said in a previous post, I think there is also some truth in the idea that there was some sort of conspiracy to restrict development of the internal combustion engine to only run on oil, or am I being paranoid

 

[Deleted member 2227]

So is a 220 diesel better than a C180k from the environment point of view?

 

[grober]

From what I can see

c220cdi diesel saloon/estate man/auto up to 225 tyres --7 stars
can lose a star to 245 tyres.

c180k saloon manual 6 stars up to 225 tyres
loses a star to automatic---5star
loses a star to 245 tyres----4 star ( estates only listed with 245 tyres??)
from that
c220cdi auto better in saloon
than
c180k auto saloon
by 2 stars if you stick to 225 tyres in both

whatever 2 stars means . SO I GUESS THE ANSWER IS YES

 

[big x]

Old style diesels are an environmental disaster area http://www.abc.net.au/health/regions/features/diesel/

adam

 

[jeremytaylor]

Depends on how you define "Green"!

However:

http://www.eta.co.uk/tools/car-buyers-guide.asp

The ETA figures ignore the damaging side effects of manufacture and disposal of hybrid batteries. There were some figures from the USA recently which included manufacturing damage and the Prius came way down. Top rank went to a Jeep (don't ask me how).

Lowest fuel use must rank highly - which tends to favour diesels, so long as particulates are trapped/burnt off.

 

[Dieselman]

Old style diesels are an environmental disaster area http://www.abc.net.au/health/regions/features/diesel/

adam

Hmm.
This is an out of date report that is at odds with recent thinking on pollution.

It specifically mentions particulates. These used to be a massive buzz word for anti diesel lobbyists, until it was pointed out that petrol engines actually emit greater numbers and, as this report accurately states, the ultra fine ones are the ones that can pass through the lung wall.

Guess which fuel type produces more ultra fine particulates?

Remember that Australian sudies aren't really representative in Europe because we use higher grade, much lower sulpher diesel oil. This effectively reduces emmissions significantly.

About ten years ago both VAG and Bosch were quoted as asking why does everyone go on about particulates when it is such a small amount of the overall polution issue for diesel engines?
the answer is simple really, it's because they can be seen so are deemed pollution and also because the popular belief was that they only cme from diesel engines.

There was a study carried out in an American town that showed that people with respiratory problems or infections were more likely to die when there was greater airborne pollution, particularly naming particulates.
This was extrapolated by the British press to be 10,000 deaths in Britain per year from diesel particulates.

What they "forgot" to mention was that the town in question had no diesel vehicles, even the busses were petrol.

Also mentioned in the quoted study is that workers in industries that use diesel engines suffer greater incidences of cancer.
That is at odds with the HSE study over 50 years of this situation, who say there is no connection to illness and working with diesel engines. I understand this to be the largest and longest study in the World.

 

[Dieter]

Hi,

Diesel.

"Diesel powered cars generally have about a 40% better fuel economy than equivalent gasoline engines[1] and produce only about 69% of the greenhouse gases. This greater fuel economy is due to the higher per-liter energy content of diesel fuel and also to the intrinsic efficiency of the diesel engine. While diesel's 15% higher volumetric energy density results in 15% higher greenhouse gas emissions per liter compared to gasoline[2], the 40% better fuel economy achieved by modern diesel-engined automobiles offsets the higher-per-liter emissions of greenhouse gases, resulting in significantly lower carbon dioxide emissions per kilometer.[3][4]"

Click here for more info: http://en.wikipedia.org/wiki/Diesel

Cheers,

 

[BenzComander]

The argument is fundamentally flawed in any case, as oil based fuels are consigned to history.

The future is Lithium Ion battery power, if Silicon Valley is to be believed!

A recent article in Car magazine highlighted this, the Tesla Roadster, which is powered by posh mobile device batteries!

Seems the car makers are heading in the fuel cell direction, whereby the people that brought us PC's, the Internet, mobile phones, iPods etc now want a piece of the car market. They are not hamstrung by being tied to the oil industry, and are looking at cars as just another consumer item, such as a mobile phone. Their perceived advantage over the car industry is they have a far greater knowledge of electronics, and the miniaturisation of electronic systems

 

[Robbo]

I sure hope they improve the technology of lithium ion cells though, these cells have a finite lifetime (time-span as well as no of charges) which is degraded rapidly when warm (think hot car in summer). I for one wouldn't want to be changing the batteries every 18 months! i'm sure that's not too green!