Boot space optimisation

Boot space optimisation /boot spayss op-ti-my-zay-shuhn/ noun (uncountable)

Boot space optimisation is the engineering and design practice of maximising the usable luggage capacity within the rear compartment of a motor vehicle. This is the dark art of making a car's hindquarters capacious enough for the annual family holiday to Cornwall, a battle fought in millimetres against intrusive suspension, fuel tanks, and the once-sacred full-size spare wheel. For many British car designers, this was often a secondary concern to getting the rear styling just right, leading to cars with vast-looking boots that could barely swallow a briefcase. It is the science of packaging that separates a truly practical family car from one that just looks the part until you try to load a pram into it.

The Full Story of Boot Space Optimisation

In the early days of motoring, luggage was your own problem. You bought a trunk from a luggage maker and strapped it to a metal rack on the back of the car. The integrated boot was a later development, and for decades, it was treated as little more than a metal cave of awkward dimensions, usually compromised by having the spare wheel bolted vertically in the middle of the load floor.

The real quest for a usable boot began with the post-war family saloon. Cars like the Ford Consul and Morris Oxford were workhorses, and their owners expected to be able to carry things. Still, the traditional front-engine, rear-wheel-drive layout, with its bulky live rear axle and differential, placed hard limits on the shape and depth of the boot.

The great leap forward, as with so many things in British car design, came from the mind of Alec Issigonis. His masterstroke with the 1959 Mini was turning the engine sideways and driving the front wheels. While the Mini's own boot was famously tiny, barely large enough for a handbag and a sense of disappointment, the principle it established was revolutionary. By cramming the entire drivetrain into a compact unit at the front, the rest of the car's length was freed up for people and their possessions.

This principle led directly to the hatchback. The Austin Maxi of 1969, another Issigonis design, was arguably the first to combine the transverse-engine layout with five doors, creating a family car with a load bay like a small van when the seats were folded. This was a moment of sheer packaging genius. The hatchback layout, later popularised by the Volkswagen Golf, became the ultimate expression of boot space optimisation in a small car.

In more recent times, the battle has been against the increasing complexity of modern cars. Sophisticated multi-link rear suspension systems, which give a much better ride, have struts and arms that poke into the luggage area, ruining the nice, boxy shape that designers crave. Crumple zones and crash structures also eat into available space. This led designers to declare war on the biggest space-waster of them all: the spare wheel. First, it was replaced by the skinny, temporary "space-saver". Then, it was eliminated altogether in favour of a can of sealant and a small compressor. While loathed by many, the demise of the spare wheel has liberated a huge amount of underfloor storage, creating the hidden compartments and variable-height boot floors common today.

For The Record

What is the biggest enemy of boot space?

Intrusive rear suspension. A simple, compact torsion beam or live axle allows for a wide, deep boot. A sophisticated multi-link suspension system, while offering a better ride, has struts and arms that invade the luggage area, creating an awkwardly shaped space with lumps and bumps.

Why was the transverse engine so important for packaging?

By placing the engine and gearbox sideways across the front of the car, it created a very short nose and contained all the mechanical parts in one compact area. This left the majority of the car's length for passengers and their luggage, a revolutionary change from the traditional layout, which had a long engine bay and a bulky transmission tunnel running through the cabin.

Do saloon cars have less usable space than hatchbacks?

Almost always. A saloon's boot has a fixed parcel shelf and a smaller letterbox-style opening, making it difficult to load bulky items. A hatchback's large, top-hinged door and the ability to fold the rear seats create a much larger and more versatile load space, even if the total volume measured in litres is similar.

What is a 'Litre VDA'?

It is a standardised German method (Verband der Automobilindustrie) for measuring boot capacity. It involves physically filling the space with standardised one-litre blocks (sized 200x100x50mm). This gives a realistic, comparable figure for usable space, rather than just an optimistic calculation of the raw volume of the empty void.

Why have spare wheels disappeared?

A combination of cost-cutting, weight saving (for better fuel economy and emissions), and the desperate need to free up boot space. The increased reliability of modern tyres and the prevalence of breakdown services have allowed manufacturers to decide that a can of sealant and a prayer is an acceptable compromise for most drivers.