A cold week asks more of a small EV than the mild-day figure

The figure printed for a mild day is a poor guide to a cold commute. We kept the desk hatchback on one loop for six mornings in a mild spell and six mornings after the temperature sat near freezing overnight. The car, the driver, and the route did not change. The energy use did.

What the log actually showed

In the mild spell the trip computer settled around 11.8 kWh per 100 km. On the cold mornings, with the cabin set to 20°C and the car unplugged overnight, the same loop sat around 16.4 kWh per 100 km. That is not a brochure range. It is our loop, our car, and a stopwatch. It is enough to say the gap is large, and that it shows up before you have left the district.

The first three kilometres were the expensive ones. The heater was working hard, the glass was still misted, and the battery had not come up to a temperature it liked. After that the number improved, but it never returned to the mild-day figure on a trip that short. A long highway run would tell a different story. Most of the driving this desk actually does is not a long highway run.

Where the energy went

Some of the loss is the cabin. Resistance heating, or a heat pump that still has to work, is a second load sitting on top of the motor. Some of it is the battery itself: a cold pack accepts and gives energy less willingly, and the car spends effort warming it. Some of it is tyres and grease that have gone stiff. None of that is a scandal. It is physics, and it is poorly served by a single number gathered on a mild day.

We also tried preheating while the car was still plugged in, for twenty minutes, on three of the cold mornings. The gap did not vanish. It shrank by roughly a third on those mornings. The cabin was already warm, the glass was clear, and the pack had a head start. If you can charge where you sleep, that is the cheapest range you will buy all winter. If you cannot, the honest move is to plan the week off the cold number, not the mild one.

How to read a sticker in September

A buyer comparing two small electric cars in early autumn should ask what the car does on a short, cold trip, not only what it does on a gentle loop in June. Our log is one car. It is not a league table. It is a reminder that the painful part of winter range is often the first kilometres with the heater on, and that a plugged-in preheat is worth more than another decimal on a mild-day claim.