To have any genuine validity, any calculations about the environmental footprint of a vehicle need to be ‘whole of life’ calculations, i,e, from the cradle to the grave. It makes sense that a car’s annual carbon footprint is 1/l*tc+ac, where l= lifespan (total number of years predicted use), tc= total carbon involved in manufacture, and ac= the amount of carbon produced by the vehicle during its use in a year.

But just defining the tc is a hugely complex calculation and there are as many definitions as there are people defining them. A rough rule of thumb is that a small (Toyota Aygo size) car has a footprint when rolling off the line of around 7 tonnes, while a top spec 4×4 (Land Rover DIscovery size) is up to 35 tonnes. Modern cars are less prone to the tinworm which consigned cars built last century to an early grave, and should have a lifespan of perhaps 15 years. To keep the calculation fair, we’ll enter the same mileage that the average classic car owner does in his car per year according to the Centre for Economics and Business Research report, of 1,200 miles. My modern Volvo XC90 turns out 340kg of carbon to do that distance, but let’s be generous and use the much smaller Toyota Aygo as mentioned above, which generates a slightly more reasonable 230kg. By comparison, the classic car churns out 560kg, more than twice as much. But, using the formula above, we have to add 1/15th (1 year from a 15 year lifespan) of 7 tonnes ‘creation footprint’ which equals 466kg to the Aygo figure, to get a total of almost 700kg. Since it was built at least thirty years ago, sometimes much more than that, the classic vehicle has long ago paid off its carbon debt, making it comfortably less polluting overall than even a clean supermini.

Some guy called Disraeli had something to say about statistics, but it’s fair to say that there is at least room for debate about classic cars, and that’s before you consider the huge amounts of money generated annually by the classic industry. If you fancy reading (much) more informed data on the subject, you can download the CEBR report free here and while away an hour or two, or start a conversation on the MMOC Facebook group at facebook.com/groups/morrisminors where we’ll be glad to chew the cud with you.