The two fixed costs that weigh most at home: your car and your electricity

Almost everyone knows what it costs to fill the tank and almost nobody knows what their car costs. They are very different things: fuel rarely exceeds a third of the real expense. Counting only what you pay at the pump is like working out the cost of a house by looking solely at the electricity bill.

Fixed vehicle costs

• •Insurance: €400–1,200/year depending on cover and driver
• •Road tax (IVTM): €50–200/year depending on municipality and engine power
• •MOT: ~€50 every 2 years (every 4 years for new cars, then every 2)
• •Annual service: €150–400
• •Tyres: ~€400 every 30,000–40,000 km

These costs share an uncomfortable feature: you pay them the same whether you drive 5,000 or 30,000 km a year. That is why the per-kilometre cost of a light user rockets: the same €1,500 of fixed costs spread over fewer kilometres gives a far worse figure per kilometre. A car sitting in the garage still costs money every day.

Variable costs: fuel

Fuel is the most significant variable cost. A diesel using 6 l/100 km at €1.45/l spends ~€8.70 per 100 km. A petrol car using 8 l/100 km at €1.60/l spends €12.80/100 km. An electric using 18 kWh/100 km at €0.20/kWh spends just €3.60/100 km.

Depreciation: the invisible cost

Depreciation is the biggest car cost but the most ignored. A new car loses 15–25% of its value in the first year and 10–15% in subsequent years. A €25,000 car you use for 10 years and sell for €5,000 has cost you €20,000 in depreciation alone: €2,000/year.

Cost per kilometre

Adding all items (fixed + variable + depreciation), the true per-kilometre cost of a mid-range car in Spain typically falls between €0.30 and €0.60/km. This means a 20 km journey costs €6–12 — similar to or higher than a shared taxi for the same trip.

That figure changes quite a few everyday decisions. If you drive under 8,000 km a year, a mix of public transport, the occasional taxi and car hire for long trips usually works out cheaper than ownership, while sparing you parking and breakdowns. Above 15,000 km a year, or if you live where public transport is thin, the balance tips clearly the other way.

New, nearly new or second hand

Because depreciation is the largest cost and concentrates in the early years, buying a two- or three-year-old car lets the first owner absorb the heaviest hit. A three-year-old vehicle has already lost around 40% of its value but retains most of its useful life and often still has warranty cover. In purely economic terms, it is the most efficient point to buy.

The other fixed household cost: the electricity bill

Cutting your electricity bill is not about switching off light bulbs, but about knowing where the money actually goes. Most of the advice in circulation targets negligible consumption while ignoring the three or four appliances that account for half the bill. It is worth ordering the problem by size before changing any habits.

How to read your bill first

A Spanish electricity bill has two distinct blocks. The capacity charge is paid every month whether or not you switch anything on, and depends on the kilowatts you have contracted. The energy charge depends on what you consume. Many households have more contracted capacity than they need, inherited from an old installation or a sales recommendation, and that is money paid for nothing in return.

The big consumers in the home

• •Electric heating and AC: 1,500–3,000 W, the year's biggest consumption
• •Electric water heater (tank): 1,500–2,500 W, up to 800 kWh/year
• •Tumble dryer: 2,000–3,000 W per cycle (~2–3 kWh)
• •Electric oven: 2,000 W; 1 hour of use = 2 kWh
• •Refrigerator: 100–200 W but runs 24h → 500–900 kWh/year

The pattern worth remembering is that anything producing heat or cold consumes a lot, and anything producing information consumes little. A hairdryer uses more in ten minutes than a laptop does across a full working day. That is why climate control, hot water and the tumble dryer concentrate the bulk of spending in almost any home.

Small consumers that are always on

Standby and small devices on idle add up unnoticed: the router (10–15 W × 8,760 h = 88–131 kWh/year), the TV set-top box, chargers plugged in unused. Although individual consumption is small, the total can represent 5–10% of the annual bill.

PVPC vs. flat rate: making the most of off-peak hours

If you have a PVPC tariff (hourly market price), electricity is cheaper in off-peak hours (generally overnight). Programming your washing machine, dryer or dishwasher to run from 11pm–7am can reduce those cycle costs by 40–60%. With flat-rate tariffs this trick has no effect.

Measures with the highest return on investment

• •Switching to LED bulbs: 70–80% saving on lighting
• •Good home insulation: reduces heating/cooling costs by 30–50%
• •Installing a smart thermostat: up to 20% saving on heating
• •Energy-efficient appliances (A+++): up to 50% less than equipment from 10 years ago

When weighing these measures, think in years to payback rather than percentages. Changing bulbs pays for itself in months. A smart thermostat, in a couple of seasons. Replacing a fridge that still works purely for efficiency rarely pays off before eight or ten years, so it makes more sense to do it when the old one fails than to bring it forward.

The thermostat degree

Every extra degree on the thermostat raises heating costs by around 7%. Going from 23 to 20 degrees in winter cuts close to a fifth of climate-control consumption, which is the largest annual item in most homes. No other zero-cost measure comes close in impact.

The same applies in reverse with air conditioning: dropping from 26 to 22 degrees in summer can double the unit's consumption. The usual recommendation of 21 degrees in winter and 26 in summer is not an arbitrary figure, but the point where comfort and cost balance reasonably.