A vehicle is either a substantial asset in an emergency or a two-tonne ornament with an empty tank, and which one it is gets decided weeks earlier by a habit that costs nothing.
The fuel half of this page carries real hazards, and the hazards are not the ones people expect: it is the vapour rather than the liquid, and it is carbon monoxide rather than fire that kills most often.
The habit that matters most
Keep the tank above half.
That is the whole of the most useful advice here. A half tank is enough to get out of the area, to run a heater for a while, to charge phones, and to reach somewhere useful. An empty tank on the morning of a fuel shortage is a car you cannot use and cannot refill, because everybody else is at the same pumps.
It costs nothing. You buy the same fuel over a year either way; you simply buy it earlier. The only cost is filling up more often.
Fuel shortages are self-reinforcing. Everybody topping up at once empties the forecourts within a day, entirely independently of whether there was a real supply problem. The households that are unaffected are the ones that were already above half.
Keeping the vehicle serviceable
- Tyres, including the spare. Pressure, tread and condition. Find out whether you have a spare at all: many modern cars have a can of sealant instead, which is useless on a sidewall cut.
- Know where the jack, the wheel brace and the locking wheel nut key are. The key is the classic: it lives in a glovebox, gets moved, and is discovered missing at the roadside.
- Change the wheel once, in the driveway, in daylight, before you ever have to do it in the rain on a verge.
- Battery. The commonest cause of a car that will not start, and it fails in cold weather. If it is more than four or five years old, replace it before winter rather than after.
- Coolant, oil, screenwash, wipers. All cheap and all capable of stopping a journey.
- Service it. A vehicle you are relying on is not the place to defer maintenance.
- Keep the documents current and know where they are.
What lives in the boot
Check it twice a year when the clocks change, along with the smoke alarms.
Storing fuel legally
The UK rules are specific and it is worth following them exactly.
Use proper fuel containers, which are marked as such, coloured by convention, and designed to vent safely. Old drums, water containers, jerry cans of unknown provenance and anything not intended for fuel are neither legal nor safe.
Diesel is not covered by the petrol rules and is far less hazardous, though the storage sense below still applies.
Check your insurance and, if you rent, your tenancy. Both may say more than the law does.
Storing fuel safely
Fuel goes off
The part that catches out everybody who stores fuel and never rotates it.
Petrol degrades within about six months. The light fractions evaporate, it oxidises, and it gums up. Modern petrol containing ethanol is worse, because ethanol absorbs water from the air and can separate out, leaving a layer of water and alcohol at the bottom of the container that will not burn.
Old petrol will not start an engine, and it will foul the fuel system of one that was working.
Diesel keeps longer, a year or more, and has its own problem: microbial growth at the interface between fuel and any water, commonly called diesel bug, which blocks filters.
So rotate.
- Every six months, pour the stored petrol into the car and refill the containers fresh. Diarise it with the clock change.
- Fuel stabiliser extends petrol life to perhaps a year and is worth adding if the fuel will sit.
- Keep containers full rather than part full. Air space means condensation, and condensation means water in the fuel.
- Store cool and out of sunlight, which slows degradation considerably.
- Label each container with the date it was filled.
Never run an engine indoors
The car as a resource
Even parked, it is useful, and this is worth knowing.
- A charger, for phones and, with an inverter, small devices. It will do this on very little fuel.
- Shelter. Dry, out of the wind, and lockable.
- A radio with a decent aerial, which will often receive better than a handheld set.
- Light, from the headlights and the interior lamps, though sparingly.
- A reserve of fuel for a generator or a stove, though only with a proper siphon pump and only with the same care as above.
- A visible marker with the hazard lights on, if you need to be found.
It will flatten its battery if you run electrics with the engine off. Run the engine periodically, outdoors, or use a jump pack.
When not to drive
- Through any depth of moving water. See river and flood crossings. A car floats in far less water than people expect and most flood deaths involving vehicles are people who drove in.
- Into an area being evacuated, against the flow.
- When the roads are gridlocked, which turns the car from an asset into a trap with a finite fuel supply. Being stationary in traffic in winter is a genuinely dangerous situation and it is why the boot kit exists.
- When you are exhausted. Tiredness at the wheel is the risk that gets ignored in emergencies.
- When walking is more reliable. Over short distances, in gridlock or on damaged roads, on foot is often faster and always more predictable. See moving on foot safely.