It seems that diesel is finished. For years, it was promoted as the greenest of engines, but now Boris Johnson, London’s mayor, is pushing for government to go ahead with a diesel scrappage scheme – where drivers of older diesels are given a cash sum to scrap their old car and get a new petrol-engined car.

I hate scrappage schemes. They’re so wasteful. I know London has serious pollution issues, and diesel is a large part of that – but I can’t see Transport for London replacing its entire fleet of buses anytime soon, can you? Instead, the tax payer will once again be footing the bill for perfectly usable cars to be crushed. It boggles the mind that this could happen for a second time.

Peugeot truly nailed the diesel engine – but diesel is now dead

The first scheme was bad enough. A surprisingly large number of classic cars were traded in, along with an awful lot of low-mileage motors that had plenty of life left in them. I recall a Volvo 740 being scrapped with just 14,000 miles on the clock. Where’s the sense in that? With such low mileage, it was hardly contributing to pollution levels was it? One cow was probably more lethal to the environment.

But to be honest, diesel has been awaiting the executioners axe for some time now. In the olden days, diesels were deliciously simple. That was part of the appeal. But to improve emissions and try to compete with more efficient petrol engines, ever-more technology was forced upon them, and the engines themselves were put under greater strain. There’s no way that I would buy a brand new diesel if faced with the choice. For some years now, petrol has made a lot more sense – especially in an urban environment. Focusing purely on MPG figures ignores the fact that diesels are becoming more unreliable, and are fitted with expensive-to-replace things such as particulate filters, dual-mass flywheels, injectors and ECUs. A diesel shouldn’t need an ECU! Proper diesels can run without any electrical input whatsoever (if you remove the stop solenoid that is). But it’s nitrogen dioxide that’s the problem. If anything, all the kit to lower carbon emissions seems to make this even worse. So, Boris wants the cars that cause most problem to be scrapped!

A twit and a diesel-burning bus

But paying people to change cars seems a bloody stupid way of dealing with the pollution problem. Surely the problem is that people still insist on driving fossil-fuel burning vehicles in a crowded city? Why on earth they keep doing this is utterly beyond me. Even I, a confirmed petrolhead, would rather sit on a bus than travel around London in a car. City driving is to motoring what wasps are to a picnic. Horrible. The car is meant to be about freedom, not being endlessly stuck in traffic.

But, while my anger at scrappage schemes remains unabated, I will take time to doff my cap to Rudolf Diesel’s compression-ignition engines. The theory was great, but sadly diesel’s time has come to an end. I guess the next question is, will petrol follow suit?