Horsepower flatters combustion engines. A number in the hundreds sounds powerful, impressive, competitive. The same engine expressed in watts — its actual unit of power — would be a six-digit number that invites scrutiny. 250 horsepower sounds like a lot. 186,000 watts invites the question: 186,000 watts of what, from how much fuel, at what efficiency?

Horsepower also creates an implicit scale in the consumer's mind that anchors all performance comparisons to combustion. When electric vehicles entered the market, manufacturers adopted horsepower ratings immediately — not because it made technical sense, but because it placed electric performance on a scale consumers already understood from petrol engines. The scale itself was inherited from the industry being disrupted. That is not an accident.

The energy industry benefits from public innumeracy about power. When consumers cannot intuitively translate between kilowatts, horsepower, and joules, they cannot meaningfully audit their own consumption. They cannot compare the energy cost of driving to the energy cost of heating. They cannot assess whether a policy is efficient or wasteful without specialist translation.

The persistence of horsepower as the primary public-facing unit of power keeps energy literacy low. A public that understood power in watts — a unit that applies equally to a kettle, a car, a wind turbine, and a human body on a bicycle — would be a public capable of holding energy suppliers and grid operators to honest account. That is not in the supplier's short-term interest.

The problem of inherited measurement is not limited to power. The same logic applies wherever a unit was designed by one institution and is now being used — unreflectively — to measure something it was never built to describe. The credit score was designed by lenders to assess default risk for their own portfolios. It is now used to determine housing access, employment eligibility, and social trust. The unit serves the institution that designed it.

GDP measures the monetary value of transactions — including transactions that represent harm, waste, and destruction. It was designed by economists in the 1930s to measure wartime production capacity. It is now the primary metric by which governments assess whether a society is flourishing. A society that is burning its forests, depleting its aquifers, and selling its children's future shows growth in GDP. The unit was not designed to care about that. It still doesn't.

Cities were designed around the car's performance envelope — its speed, its turning radius, its parking footprint, its road width requirement — all of which were defined in an era when horsepower was the only public metric for vehicle capability. The result is infrastructure that encodes the assumptions of 20th-century combustion performance into concrete and asphalt that will last a century.

When a city zones for roads wide enough for 300-horsepower vehicles moving at 80km/h, it produces a built environment hostile to pedestrians, cyclists, and the lower-power, lower-speed movement that most urban trips actually require. The horsepower standard did not just measure performance — it defined what performance was supposed to look like. Infrastructure planners, construction firms, and road engineers all operate within a system that was scaled to that standard. Retiring the unit threatens to make visible how much of the built environment was built for the wrong reasons.