How to Look After a Car You Don’t Drive Regularly?

Leaving a vehicle inactive for too long can actually cause more damage than driving it daily. From flat batteries to seized brakes and flat spots on tyres, “mechanical stagnation” can lead to a nasty repair bill right when you need your car most. Here is the essential UK guide on how to look after a car you don’t drive regularly. 

Key Takeaways: How to Look After a Car You Don’t Drive Regularly

Leaving a car unused causes battery drain, brake rust and tyre damage. Drive it occasionally, maintain fluids, prevent damp, use a charger, and stay legally covered with MOT, insurance or SORN.

• Cars suffer more from inactivity than regular use due to battery drain, brake corrosion, tyre flat spots, stale fuel, and damp interiors. 
• Don’t just idle the engine. Drive the car for 15–20 minutes or use a trickle charger instead. 
• Keep tyres slightly over-inflated, the fuel tank full, and fluids checked, even if mileage is low. 
• Use a breathable car cover only on a clean, dry vehicle. 
• Protect the interior from damp using moisture traps and regular airing. 
• Stay UK-legal with MOT, insurance, or SORN, depending on how the car is stored. 
• EVs and hybrids need different care: store the battery at 50–80%, and don’t forget the 12V battery.

Why Cars Suffer When They Are Not Driven Often

It sounds contradictory, where low mileage is a good thing. While low mileage adds value, total inactivity can destroy your car. Because the car is designed to move.

• Batteries drain faster: Even when the engine is off, modern cars use a small amount of electricity for alarms, clocks, and computers. 
• Tyres can develop flat spots: The weight of the car can leave permanent marks if the vehicle isn’t moved. 
• Brake corrosion happens quickly: Brake discs can rust, making the brakes noisy or less effective. 
• Fluids degrade over time: Engine oil, brake fluid, and coolant lose effectiveness if the car isn’t running. 
• Interior and exterior damage: Moisture can build up, causing mould inside and paint damage outside.

Essential Maintenance Checklist for a Car You Don’t Drive Regularly

1. Keep It Covered

If you have a garage, use it. It’s perfect to protect against UV rays, bird lime, and tree sap.

If you are parking outside, be careful with car covers. A cheap, plastic waterproof sheet might seem like a good idea, but it often does more harm than good. 

These covers trap moisture between the plastic and your paintwork, acting like a greenhouse that breeds mould and rust.

It is important to get a breathable, multi-layer outdoor cover. This allows moisture to escape while blocking rain and sun. If you can’t get a cover, try to park in a shaded area, but avoid parking directly under trees.

2. Clean and Protect the Car

Before you leave the car for a long stint, give it a proper wash and dry. Do you know why? Because bird droppings and dead bugs are acidic. If left on your paintwork for weeks, they will etch into the clear coat, leaving permanent scars.

To protect your car, apply a coat of quality wax or a sealant. This acts as a sacrificial barrier, protecting the paint from the elements while you’re away. And also coat wheels, brakes and bumpers.

3. Look After the Battery

Modern cars are power-hungry. Even when the engine is off, the alarm, immobiliser, and onboard computers are sipping electricity. In as little as two weeks, a healthy battery can drop below the voltage needed to start the engine.

The best option is a smart trickle charger, also known as a battery conditioner. These devices monitor your battery and gently top it up only when needed.

If you park on the street and can’t run a cable, consider a solar battery maintainer that plugs into your OBD port or attaches to the dashboard.

4. Check Tyre Pressures

Tyres are flexible rubber rings holding up 1.5 tonnes of metal. If they stay in one position for too long, the weight flattens the bottom of the tyre where it touches the road. 

The solution is to inflate your tyres to roughly 40 PSI or about 10-15 PSI higher than your normal pressure before storing the car. This extra firmness helps them hold their round shape.

5. Check and Top Up Fuels

This is one of the most important checks that you should understand. In the UK, standard petrol is now E10 (containing up to 10% renewable ethanol). Ethanol attracts water from the air. So Fill the tank to the brim

If you leave a tank half-empty, the air space inside the tank allows condensation to form. The ethanol absorbs this water, which can corrode the inside of your fuel tank and fuel lines.

Less air space means less moisture. If you are storing the car for more than 3 months, consider adding a fuel stabiliser to keep the petrol fresh.

6. Protect the Interior from Damp

The UK is a damp island. Without the heater or air-con running, the air inside your car can become stale and moist, leading to mould on the steering wheel and seatbelts.

Remove all rubbish, especially food wrappers, which attract rodents. Then, place a passive dehumidifier, like a moisture trap tub or a few bags of silica gel. These will soak up excess moisture and keep the interior smelling fresh.

7. Stay Legal: MOT, SORN and Insurance

Just because you aren’t driving doesn’t mean the paperwork stops.

• SORN: If you want to stop paying road tax and insurance, you must officially declare the car off the road with a SORN (Statutory Off Road Notification) via the GOV.UK website.
• MOT: You generally cannot drive a SORN car, with one exception: driving to a pre-booked MOT test.
• Insurance: If you don’t SORN the car, you must keep it insured (Continuous Insurance Enforcement rules). Even if you do SORN it, consider “Laid Up” insurance (often called “Fire and Theft” cover) just in case.

8. Don’t Just Start the Engine and Leave It Idling

This is the most common mistake car owners make. You might think starting the car for 5 minutes “charges the battery” or “warms it up”.

The reality is idling doesn’t generate enough heat to burn off the condensation inside the engine, and it often drains the battery faster than the alternator can recharge it at idle speed.

The Golden Rule is to either drive the car for at least 15-20 minutes to get the oil hot and the battery charged.

Checklist: How to Look After a Car You Don’t Drive Regularly

Area	What to Do	How Often	Why It Matters
Battery	Use a trickle charger or drive 15–20 mins	Weekly / Fortnightly	Prevents flat or sulphated batteries
Tyres	Inflate to +10–15 PSI above normal	Before storage	Avoids flat spots and tyre damage
Fuel	Keep tank full, add stabiliser if storing	Before storage	Prevents condensation and fuel corrosion
Brakes	Drive and brake gently	Weekly	Clears surface rust from discs
Engine	Avoid idling only	Always	Reduces condensation and oil dilution
Fluids	Check oil, engine coolant, and brake fluid	Monthly	Fluids degrade over time, not mileage
Interior	Use moisture traps, remove rubbish	Monthly	Prevents mould and damp smells
Exterior	Wash and wax before storage	Before storage	Protects paint from corrosion
Cover	Use breathable cover only	When parked	Prevents trapped moisture
Legal	Check MOT, SORN, insurance	Ongoing	Avoids fines and invalid insurance
EV Battery	Store at 50–80% charge	Long-term parking	Reduces lithium battery degradation
EV 12V Battery	Keep plugged in or maintained	Long-term parking	Prevents total vehicle shutdown

 

What to do When Leaving Your EV & Hybrid Car Parked?

If you have an electric vehicle (EV) or a plug-in hybrid (PHEV), the rules of storage are different. While you don’t need to worry about stale petrol unless it’s a hybrid, you do need to worry about battery drain.

Leaving an EV parked incorrectly can actually damage the expensive lithium-ion cells. Here is the 2026 standard for keeping your battery healthy while it sleeps.

1. The 50–80% Charge Rule

Never store an EV with a battery at 100% or near 0%.

• At 100%: The battery cells are under high chemical stress. Leaving it fully charged for weeks can accelerate degradation, permanently reducing your range.
• At 0%: You risk “bricking” the battery. All batteries self-discharge slightly over time. If it drops below critical voltage, the car’s management system may shut down completely to protect safety, often requiring a manufacturer reset.
• The Fix: Aim for a “State of Charge” (SoC) between 50% and 80%. This is the battery’s happy place where chemical stress is lowest.

2. Watch Out for 12V Battery 

Many owners forget that EVs still have a standard 12-volt lead-acid battery (just like a petrol car) to run the locks, alarm, and computer. If this small battery dies, the big high-voltage battery disconnects for safety, and you won’t be able to “start” the car or even open the doors.

If you are leaving the car for more than a month, check your manual. Some manufacturers (like Tesla) recommend keeping the car plugged in to a home wall box with a charge limit set to 50%. The car will automatically tend to the 12V battery for you.

Frequently Asked Questions

How often should I start my car if I’m not driving it?

Simply idling the engine on your driveway for 10 minutes does more harm than good. It creates condensation in the exhaust and often drains the battery faster than the alternator can recharge it at idle speed.

To actually recharge the battery and warm the oil, you need to drive the car for at least 15–20 minutes. If you can’t do that, it is better to leave the engine off and use a trickle charger.

What happens if you don’t drive your car for 6 months?

Leaving a car untouched for half a year can cause significant mechanical stagnation. The battery will be dead and sulphated. The tyres get flat, and the brake pads will likely have rusted to the discs. Lastly, engine oil may separate, and modern E10 petrol will likely have absorbed water, potentially corroding the fuel lines.

How long can you leave a car without starting it?

 If the car is prepared correctly (battery on a charger, tyres over-inflated, fuel stabiliser added), a car can sit safely for 6 to 12 months. However, without any preparation, a modern car’s battery will typically die within 2 to 4 weeks due to the parasitic drain from the alarm and immobiliser.

Does a car battery drain if not used?

All batteries suffer from natural self-discharge, losing a small percentage of power every week, even if disconnected. In a connected car, this is accelerated by parasitic loads – power silently used by the alarm, clock, and keyless entry receivers. This is why a battery can go down even if you turn the headlights off.

How long is a SORN valid?

A SORN (Statutory Off Road Notification) is valid indefinitely. Unlike in the past, you no longer need to renew it annually. The SORN only expires when you tax the vehicle again, sell it, or scrap it. Remember that a SORN vehicle must be kept on private land and cannot be parked on a public street.

Wrapping UP: How to Look After a Car You Don’t Drive Regularly

Looking after a car you don’t drive regularly doesn’t require hours of work. It just requires a little strategy. By keeping the battery charged, the tyres inflated, and the fluids fresh, you are ensuring that your car starts perfectly after its hibernation. It is ready to go, not ready for the scrapheap.