How to store your 80s icon for the winter

The humidity trap in South West England

The climate around Bristol is particularly tough on older cars. Between November and March, the average outdoor humidity levels often stay above 78%. In our workshop on Queens Square, we have seen dozens of cars arrive in spring with fuzzy white mould growing on the seatbelts and steering wheels. This usually happens because owners think a closed garage door is enough protection. It isn't. Brick and concrete are porous, meaning moisture seeps through the walls and floor constantly. Without airflow or a dehumidifier, your garage becomes a slow cooker for rust.

We suggest using a small hygrometer to track the air quality. You can buy one for about £12. If the reading stays above 60%, you need to act. At FC Azerbaijan, we use desiccant bags placed in the footwells of the cars we store. For a standard 90s coupe, we use 4 bags of 500g each. These bags pull moisture out of the cabin air before it can settle into the carpets. It is a cheap way to prevent a very expensive deep-clean or a full interior restoration later on.

Floor protection is another detail people forget. If your garage has a bare concrete floor, it will pull moisture up from the ground. We recommend laying down a heavy-duty plastic vapour barrier or a set of interlocking rubber mats. We once worked on a 1989 classic that had been parked on bare concrete for 5 months. The underside was covered in a thick layer of white oxidation, even though the top of the car looked perfect. Spending £84 on floor mats would have prevented that damage.

A closed garage door isn't enough protection; brick and concrete are porous and let moisture seep through all winter.

Dealing with the E10 fuel problem

Modern petrol in the UK now contains up to 10% ethanol. This is fine for your daily driver that gets a fresh tank every week, but it is a disaster for a classic car sitting in storage. Ethanol is hygroscopic, which is a fancy way of saying it loves to soak up water. Over 90 days of storage, the fuel in your tank can separate. The water-ethanol mix sinks to the bottom, right where your fuel pump and lines are. This mixture is highly corrosive and can eat through old rubber lines in a single season.

To stop this, we suggest two specific actions. First, fill your tank to 93.6% capacity. This reduces the 'ullage' or air space at the top of the tank, which limits how much condensation can form. Second, use a fuel stabilizer that is specifically designed for E10 or E5 petrol. We have tested three different brands over the last 6 years and found that a 250ml bottle is usually enough for a 60-litre tank. It keeps the fuel chemically stable for up to 8 months.

If your car has a carburettor, like some of the early 80s icons we handle, you should run the engine with the fuel tap off until it dies. This drains the float bowls. Leaving old fuel in a carburettor over winter usually leads to a gummed-up mess that requires a full ultrasonic clean in the spring. We had a client in 2022 who ignored this and ended up with a £640 repair bill for a simple fuel system service that could have been avoided with 5 minutes of work.

Modern E10 petrol is a disaster for a classic car sitting in storage for more than a few weeks.

Battery health and electrical drain

Supercars from the 90s started using more complex electronics and early alarm systems. These systems have a constant 'parasitic draw' on the battery. A healthy 12V battery can be drained to the point of no return in just 11 to 14 days if the car is not moved. Once a lead-acid battery drops below a certain voltage, the internal plates become sulphated. This means the battery will never hold a full charge again, no matter how long you leave it on a charger.

We do not recommend just disconnecting the battery. On many 80s and 90s cars, disconnecting the power can cause the ECU to lose its 'learned' idle settings or lock the radio system. Instead, use a smart trickle charger. These devices monitor the battery and only provide power when the voltage drops. They also have a 'de-sulphation' mode that can help maintain the battery's lifespan. We suggest a 3.8-amp charger for most of the legends we see in our Bristol workshop.

Position the charger away from the battery to avoid any risk from gases, and make sure the cables are not pinched by the bonnet or boot lid. We usually run the cable through a slightly cracked window or under the edge of the bumper. If you are storing the car in a shared block of garages without power, you may have to remove the battery and keep it on a charger at home. Just be prepared to reset your clock and potentially your engine idle when you put it back in.

Tyre pressures and flat spots

Tyres are one of the most expensive consumables on a supercar, especially the rare sizes required for 80s icons. When a car sits in one spot for months, the weight of the vehicle compresses the bottom of the tyre. This causes the rubber to take a set, resulting in 'flat spots'. When you drive the car again, you will feel a rhythmic thumping through the chassis. Sometimes these spots disappear after 20 miles of driving, but often the internal structure of the tyre is permanently damaged.

The easiest fix is to over-inflate the tyres. We recommend pushing the pressure up to 48 or 52 psi for the duration of the winter. This extra internal pressure helps the tyre maintain its round shape despite the 1.5 tons of car pressing down on it. Just remember to write a big note and stick it to your steering wheel so you don't forget to lower the pressures back to 32 psi before your first spring drive. We have seen people drive off with 50 psi in their tyres, which makes for very dangerous handling.

If you want the best protection, you can use tyre cushions or 'shoes'. These are curved ramps made of high-density foam that cradle the tyre. They increase the contact patch and distribute the weight more evenly. We have 12 sets of these in our facility and they work exceptionally well for cars with very wide rear tyres, like the 335-section rubber found on some 90s posters. For £150, they are a solid investment compared to the £800 cost of a new pair of rear tyres.

Write a big note and stick it to your steering wheel so you don't forget to lower the tyre pressures in spring.

The pre-storage deep clean

Never put a dirty car into storage. It sounds obvious, but even a thin layer of road salt from a late October drive can cause massive damage if left for 4 months. Salt is highly corrosive and thrives in the damp air of a garage. We give every car a full underbody wash before it goes into our storage area. We pay close attention to the wheel arches and the areas behind the plastic liners where mud and salt tend to collect and rot the metal from the inside out.

Inside the cabin, make sure you remove every scrap of food or organic material. We once had a car where a single forgotten chocolate bar attracted a mouse. In just 3 weeks, the rodent had chewed through the main wiring loom and used the seat stuffing to build a nest. The repair cost was over £1,800. We recommend a thorough vacuuming and a quick wipe down of all surfaces with a mild disinfectant. This removes the skin oils and food crumbs that mould and pests love.

Finally, treat the leather. We use a workshop-grade hide food that keeps the leather supple. Cold winter air can be very dry if you are using a dehumidifier, and that can cause old leather to shrink and crack. Apply the conditioner, let it soak in for 24 hours, and then buff off the excess. This creates a protective barrier against moisture and prevents the 'cardboard' feel that old Ferrari or Porsche seats get when they have been neglected in the cold.