Driving on electricity already costs about half what it costs to drive on fuel.

Over the next twenty years, that gap turns into a chasm.

Today, on European averages, 100 kilometres costs roughly 11 to 12 euros in a petrol car and around 6 in an electric one. Two forces are about to pull those numbers apart.

Electricity gets cheaper. As solar and battery storage scale, wholesale power prices fall and, crucially, the cheap hours multiply - Germany alone had over 500 hours of negative electricity prices last year. Whoever can shift charging into those hours drives on nearly-free energy.

Fuel gets more expensive. Carbon pricing on transport fuels arrives from 2027, and every year of it adds to the pump price.

Put both into a model and the cost of electric driving falls toward a third of combustion by the mid-2040s. In the chart below, one line drifts up, the other steadily down. The gap is not a rounding error. It is the running-cost advantage that eventually overwhelms every argument about sticker price.

This is the quiet engine of the transition. Not subsidies, not mandates, not moral pressure - just arithmetic that gets harder to ignore each year you keep buying fuel.

But here is the twist worth sitting with: this saving is not shared equally. It lands on some drivers years before others.

Tomorrow's question: who gets cheap mobility first? The answer is not who you would guess.