For a car of unknown fuel, the average number of miles per gallon is 33.6.
232 - This is assuming that you work a 5 day week and receive the minimum holiday entitlement of 28 days annual leave (including 8 bank holidays). This was updated in April 2009 along with the changes to the minimum holiday requirement.
To calculate ‘actual’ journey distance we take the distance that the ‘crow flies’ (i.e. in a straight line) and multiply by 1.25.
Average fuel cost (for all fuels) is taken at £1.3476 per litre. These figures are updated fortnightly. We do not take into account past changes in fuel costs. All of our calculations use the current fuel price.
The average car will emit 204.6 grams of carbon dioixide (CO2) per kilometre.
23 mg of Nitrogen Oxides are emitted per vehicle kilometre for an average petrol car with catalyst.
Particulate Matter emitted is negligible in petrol cars, but the population weighted average emissions from cars is 11 mg per vehicle mile. Diesel cars however, emit a significant amount (up to 10 times more PM).
source: www.epa.gov/otaq/emission-factors-research/420r08010.pdf, p.23.
42 mg of carbon monoxide is emitted per vehicle kilometre, for an average petrol car with catalyst.
19 mg of Hydrocarbons are emitted per vehicle kilometre for an average petrol car with catalyst.
source: 2008 survey of liftshare members
Average wear and tear cost works out at 9.02p per mile. This figure is taken from the AA’s 2012 document on ‘Running Costs’ and is based on an average purchase price for a new car of £33,500.
The circumference of the earth round the equator is 40,075.02km or 24901.46 miles.
source: David R. Lide, "Handbook of Chemistry and Physics", 81st edition, (CRC: 2000)
One hot air balloon is equivalent to 1.8 tonnes of CO2.
We assume that a tree will sequester atmospheric carbon dioxide at an average of 50 pounds of carbon dioxide per tree per year. This is the equivalent to 22.6796185 kilograms a year.
source: www.plant-trees.org/resources/Calculating CO2 Sequestration by Trees.pdf
All of our savings calculations assume that car-sharers would otherwise drive alone. Occasional/Shift journeys are counted as one-off return journeys.