Driving an Aceca Through the Winter

This article complements the one on storing an Aceca over winter, which covers laying the car up properly. This one is about the opposite choice: keeping it on the road.

The decision, for a car this rare

Around 328 Acecas were built in total, across all three engine variants, and the survivors are counted individually on this site's registry. That rarity changes the winter calculation in both directions.

In favour of using the car: a car that is used stays healthier than one that sits. Seals stay supple, brakes stay free, fuel stays fresh, and an engine that reaches full temperature regularly gives less trouble than one awakened each spring. Many of the faults blamed on winter are really the faults of standing.

In favour of caution: a damaged or corroded Aceca cannot simply be replaced, and its panels cannot be ordered. The car is aluminium over a hand-built structure, made in tiny numbers, and there is no supply of new bodywork in any ordinary sense. What winter takes off an Aceca, it takes off one of a few hundred.

Both of those are true, and the balance between them is the owner's to strike. What follows is meant to make the choice an informed one, not to push it either way.

Salt matters more than any product

Road salt is the one winter hazard that dwarfs all the others. Salt dissolves in the water film on the underside of the car, and in solution it keeps corroding metal for as long as it stays damp. That has a consequence many owners miss: a car put away wet and salted is worse off than one left standing in clean rain, because the garage keeps the salt solution damp and active for weeks. Rainwater on its own dries and largely stops working; salt water does not.

It follows that washing the underside after every salted drive is the single most effective winter measure there is, and it is the one most people skip. Get water underneath the car: along the chassis members, into the wheel arches, over the suspension and the floor. A hose and patience will do most of it. One caution on method: a high-pressure jet wash can drive water into seams, bearings and trim where you would rather it did not go, so favour flow over pressure and keep the lance back from anything delicate.

The corollary is that the decision about driving is really a decision about washing. If you will wash the car properly afterwards, a dry salted run is survivable. If the car will go back into the garage wet and salted, it would have been better left there.

What is specific to the Aceca

Much winter advice applies to any old car. Three things are particular to this one.

The construction

The Aceca's body is hand-formed aluminium over a composite frame of steel tube and ash timber, described in detail in the article on the body and ash frame and on the car's construction page. That construction gives the car two decay paths in winter rather than the plain steel car's one: the timber can rot if it stays wet, and where aluminium panels meet steel framing in the presence of salt water there is the further question of galvanic corrosion between the dissimilar metals. The archive would not overstate that point, and exactly how it behaves in each car depends on how the joints were made and have been kept, but it is a materially different winter risk from an all-steel body, and it is why water trapped in the structure matters more here than surface rust on a wing.

The hatchback

The Aceca's rear hatch was one of its innovations, and after seventy years its seal is an old seal. Water that gets past it collects in the load area beneath, which will hold it quietly against the structure. After wet use, open the hatch, feel the carpet and the floor of the luggage deck, and dry anything that is damp before closing the car away. It takes a minute and it is the kind of small check that prevents the kind of large repair this car cannot easily absorb.

Parts

There is no supply of new panels for these cars in any ordinary sense, and very little structure either; what exists is made by specialists, by hand, at prices that reflect it. This, more than any technical point about metals or seals, is the real argument for caution. A winter's worth of neglect on a mass-produced classic is an order form. On an Aceca it is a fabrication job.

Underbody protection, honestly

The main families of underbody coating differ in principle, and it helps to understand the differences before listening to anyone's advocacy:

• Wax-based coatings such as Waxoyl and Dinitrol creep into seams and then set to a firm, waxy film. They resist being washed off, but once set they creep no further, and a cracked or missed area stays unprotected until it is redone.
• Lanolin-based coatings such as Lanoguard stay soft. They keep creeping after application, which helps them reach and keep covering seams and spot welds, at the cost of needing more frequent renewal and of holding road dirt against themselves.
• Oil-based coatings such as Fluid Film stay wettest of all, creeping furthest and never setting, which suits cavities and moving parts but means the thinnest durable film and the most frequent reapplication.

For this car there is a further complication, and the archive will be plain about it: the Aceca is not a plain steel car. Aluminium panels and timber in the body structure both change the question, and products formulated and tested for steel may not suit either. The archive cannot advise on which products, if any, are right for an Aceca's mixed construction, and it will not guess. That is a question for the AC Owners' Club or a marque specialist who has seen the results on these cars specifically.

It is also worth saying what nobody selling anything says: there is no independent comparative testing of these products worth citing, the advocates for each are sincere, and much of what is written about them online is written by people with a product to sell. This archive has no commercial interest in any of them and cannot tell you which is best. What it can say is that no coating substitutes for washing the salt off, and a coated car put away salted is still a salted car.

The practical side

Tyres. Cold rubber grips differently from warm rubber, and a classic tyre compound that was acceptable in October can feel wooden in January. If the car is laid up each autumn its tyres are ageing anyway; if it is driven through winter, tread depth and tyre age matter more than at any other season. The wheels and tyres guide covers sizes and the age rule.

Lights. Winter driving is largely about being seen. Period headlamps are modest by modern standards, so keep every lamp working, lenses clean, and be realistic about how visible a small, low, dark car is on a grey afternoon. Clean lenses and sound connections make more difference than any upgrade.

Battery. Brief, frequent use is hard on a battery: each start draws heavily and short runs may not replace it, while cold reduces what the battery can give. Watch the charging system, keep the terminals clean, and if the car does short winter runs, a battery conditioner between them is cheap insurance. The positive earth article covers the charging side of the system.

If it stops. Carry what turns a breakdown into an inconvenience: a warm coat, a torch, a charged phone, something reflective, and the number of a recovery service that will handle a classic properly. In summer a stop is a picnic; in winter it is cold, dark and wet, and the difference is preparation rather than luck.

The gearbox. Winter means traffic, and traffic means first gear at walking pace. If your car's box has no synchromesh on first, plan changes earlier and be willing to stop rather than snatch at it; the article on driving a non-synchromesh first gear explains the technique. Cold gear oil also makes every change stiffer for the first few miles, so give the box time to warm before asking anything hurried of it.

When not to go out

Some days the answer is simply no. Ice is one: a light car on narrow period tyres has little margin, and the car it slides into will not be the one that cannot be repaired. Standing water is another: it hides potholes, floods brakes and ignition, and forces spray into every seam the constructor hoped would stay dry. The day after the gritters have been out is a third: fresh salt, still wet, is the most corrosive condition the underside will ever meet.

There is no shame in leaving the car in the garage on those days. The point of owning it is that it survives, and a winter driven selectively, on dry days with a wash afterwards, gives you the health benefits of use without handing the car to the salt. The worst outcome is not the car that rests in February; it is the car that emerges in April having quietly corroded where nobody could see it.

Common questions