When calculating CO2 emissions the amount of fuel you use is more important than the fuel efficiency of your car.
It’s important to know how much CO2 emissions are created per litre of unleaded petrol so you can calculate your overall emissions.
A gas guzzling car that never gets driven will still use less petrol than a fuel efficient car that is driving all the time.
While fuel efficiency is important you need to look at the quantity of fuel you are burning to understand your impact on global warming.
How Much CO2 Emissions Per Litre Of Unleaded Petrol
According to ComCar on average:
a litre of petrol produces 2.3035 kgs of CO2
a gallon of petrol produces 19.2236 lbs of CO2
The reason that the emission weight is so high is that oxygen is added to created the CO2 when the fuel is burned. Thus making the emission weight much higher than the starting weight of the fuel.
How Much Petrol For 1 Tonne of CO2 Emissions?
To emit 1 tonne of CO2 into the atmosphere requires burning 434.12 litres of petrol.
To emit 1 ton of CO2 into the atmosphere requires burning 104 gallons of petrol.
While some cars produce less CO2 emissions than others this rough guide should suffice for most people’s use.
Diesel is slightly different. Click here to see how much CO2 emissions diesel fuel produces.
How To Calculate How Much CO2 Emissions Your Car Creates
Calculating the CO2 emissions you create when you drive is easy.
Just simply keep track of how much fuel you put into your tank each time you fill up.
The calculation is:
number of litres x 2.3035 = kgs of CO2 emissions
number of gallons x 19.2236 = lbs of CO2 emissions
So if I fill up 35L of petrol I can assume I just used 35L of petrol. So the emmissions I created would be calculated as
35 x 2.3035 = 80.6225 kgs of CO2 emissions
How To Calculate CO2 Emissions per 100km
People love to talk about fuel efficiency in Litres/100km for some reason.
Calculating your CO2 emissions per 100km isn’t too hard.
First find out how much fuel your car uses per 100km then times by 2.3035 (the kgs of CO2 emissions created per litre of fuel).
For example my Honda Jazz is estimate to use 5.2L/100km.
5.2 x 2.3035 = 11.9782 kgs of CO2 emissions per 100km
As mentioned about this isn’t going to be as accurate or informative as simply calculating petrol usage at the pump and working out your carbon emissions that way.