No CO2 figures are quoted for diesels. They produce very little. They are not tested for anything other than smoke on an MOT.
neilly
Well-Known Member
Hi Tom,
Is yours not going to get an age related plate? As it would surely be pre 2001.
My Logbook does not have a Co2 listed on the logbook, it is a 300tdi fitted in an 87 chassis.
Having said that in answer to what wammers has said, my Diesel TD5 does have a Co2 figure listed , so his statement is not strictly correct for later vehicles. But this is not relevant to your query.
Cheers
Is yours not going to get an age related plate? As it would surely be pre 2001.
My Logbook does not have a Co2 listed on the logbook, it is a 300tdi fitted in an 87 chassis.
Having said that in answer to what wammers has said, my Diesel TD5 does have a Co2 figure listed , so his statement is not strictly correct for later vehicles. But this is not relevant to your query.
Cheers
Retroanaconda
Well-Known Member
It's not quoted or published as tax based on emissions didn't come in until later.
You can work it out quite easily though, generally speaking a litre of diesel will generate about 2.67kg of CO2 when burned. So if you know what MPG you're getting you can calculate number of litres of fuel burned per kilometre and therefore the grams of CO2 emitted per kilometre.
I worked it out years ago for my 200Tdi as I needed it for the mileage claim system at work, if I recall correctly it was about 250g/km or something like that?
You can work it out quite easily though, generally speaking a litre of diesel will generate about 2.67kg of CO2 when burned. So if you know what MPG you're getting you can calculate number of litres of fuel burned per kilometre and therefore the grams of CO2 emitted per kilometre.
I worked it out years ago for my 200Tdi as I needed it for the mileage claim system at work, if I recall correctly it was about 250g/km or something like that?
Sofasurfer
Well-Known Member
That is impossible, a litre of diesel weighs under 1kg. Burning it to produce 2.67kg of CO2 would breach the 1st law of thermodynamics.
Shimsteriom
Master Procrastinator
A typo perhaps? Maybe 2.67g
Sofasurfer
Well-Known Member
Probably 
Shimsteriom
Master Procrastinator
Maybe not actually. Just Googled it and got this...Probably
https://www.eia.gov/tools/faqs/faq.php?id=307&t=9
Shimsteriom
Master Procrastinator
By my own meager calculations, burning 1 litre of Diesel would generate 1.51kgs of CO2 Unless the results of burning the Diesel are combing with part of the atmosphere to generate the CO2, in which case, it makes more sense.
Unless the results of burning the Diesel are combing with part of the atmosphere to generate the CO2, in which case, it makes more sense.
Retroanaconda
Well-Known Member
I don't know the physics behind it, but the 2.67 (ish) seems to be the generally accepted figure. The link above quotes 1 US gallon (3.78 litres) producing 22 lbs of CO2 (10 kgs) which works out as 2.64 kg/l. The link does make a good point about biodiesel though, obviously this will have an effect.
Just worked out mine again out of interest. I average 31mpg which is 0.091 litres/kilometre. Giving an emissions figure of 243 g/km CO2.
Just worked out mine again out of interest. I average 31mpg which is 0.091 litres/kilometre. Giving an emissions figure of 243 g/km CO2.
Diesels like to suck in a lot of the atmosphere via the air filter. The oxygen part of the atmosphere is used to make the diesel combust. Diesel is made up of carbon and Hydrogen. In the combustion process the Oxygen, from the atmosphere, combines with the Carbon to produce CO2 and the Hydrogen combines with Oxygen, from the atmosphere, to create H2O. If the formula for a molecule of diesel is C10H20 (you could รท 10 to simplify and get CH2 and compare this to CO2) Oxygen is nearly 16 times more dense than Hysdrogen, so when the Oxygen/Hydrogen exchange happens during combustion you end up with a gas that is 16 times more dense. Bonkers isn't it. Explains why a turbo to ram the air in is a handy addition. That's just my basic understanding. @neilly being a Pedant (notice the capital P) will, no doubt, add a bit more substance to that layman's explanation as to what's going on.By my own meager calculations, burning 1 litre of Diesel would generate 1.51kgs of CO2
neilly
Well-Known Member
Diesel:
1 liter of diesel weighs 835 grammes. Diesel consist for 86,2% of carbon, or 720 grammes of carbon per liter diesel. In order to combust this carbon to CO2, 1920 grammes of oxygen is needed. The sum is then 720 + 1920 = 2640 grammes of CO2/liter diesel.
An average consumption of 5 liters/100 km then corresponds to 5 l x 2640 g/l / 100 (per km) = 132 g CO2/km.
http://ecoscore.be/en/info/ecoscore/co2
Or from another source.
7440 / MPG = co2 g/km
https://www.eta.co.uk/2010/02/22/calculating-a-cars-co2-emissions-from-its-mpg/
Both of the above work for the D2 Td5 mpg versus the V5 stated 262 g /km.
Cheers
1 liter of diesel weighs 835 grammes. Diesel consist for 86,2% of carbon, or 720 grammes of carbon per liter diesel. In order to combust this carbon to CO2, 1920 grammes of oxygen is needed. The sum is then 720 + 1920 = 2640 grammes of CO2/liter diesel.
An average consumption of 5 liters/100 km then corresponds to 5 l x 2640 g/l / 100 (per km) = 132 g CO2/km.
http://ecoscore.be/en/info/ecoscore/co2
Or from another source.
7440 / MPG = co2 g/km
https://www.eta.co.uk/2010/02/22/calculating-a-cars-co2-emissions-from-its-mpg/
Both of the above work for the D2 Td5 mpg versus the V5 stated 262 g /km.
Cheers
That's great. Looking at actual figures, not just 16 x more dense, emphasises the difference even more. 1920 grammes of Oxygen to change 720g of Carbon to CO2 Tremendous
