Diesel is being written off

Rewind a decade and diesel was the sensible default, half the new car market, the fleet manager's fuel of choice. Today it is in structural retreat. Diesel peaked at 17.4 million cars in the third quarter of 2019. It now stands at 14.9 million. That is 2.5 million cars gone, a 14% fall from the top, and it is still shedding roughly half a million every year. Its share of the fleet has fallen from a 45.9% peak in 2018 to 36.6% now.

This is the Red List face of the electrification story. Where the EV piece celebrates what is arriving, the same data read backwards is an obituary. For every quarter battery electric climbs, diesel drops, and the gap the EVs are filling is largely the one diesel is leaving.

The causes are cumulative rather than any single blow: the reputational damage of the emissions scandal, the spread of clean air and low emission zones into every major city, tax that increasingly punishes it, and, decisively, the arrival of credible electric and hybrid alternatives at last. None of these reversed diesel overnight. Together they have made it a fuel with no new story to tell.

Petrol is quietly past its own peak too, having topped out back in 2004 and now down 15% from there. But diesel's decline is faster, steeper and, on this evidence, terminal. It will not vanish this decade, there are still fourteen million of them, but the direction is fixed and the pace is picking up.