Wide load

Take a more modern example, the new Peugeot 308 which I drove the other day. This family hatchback is 114mm longer than its predecessor and 48mm wider. Better cabin space screams the marketing, forgetting the fact that this now 4367mm-long car is in danger of bursting out of its class.

But our roads aren’t getting any bigger and with ungraded roads occupying the lion’s share of the UK’s 246,700 miles of highway in 2018, these wider cars are having to tiptoe round each other and other vulnerable road users such as pedestrians, cyclists, motorcycles and horse riders. The evidence of how well this is going can be seen in the accident figures. Taking 2019 data to rid the effect of Covid-19, the casualty rate per billion road miles for pedestrians was 1640, cyclists 4891 and motorcyclists 5051, although of those groups, motorcyclists had by far the worst death rate per billion miles of 104.6. Then came pedestrians at 35.4 with cyclists at 29. Equivalent figures for cars are 195/1.6.

And even if far from all these accidents (or hold ups) are to do with wider cars, you can see the evidence of this widening tendency on any small road, where verges are littered with broken wing mirrors and glass marking the point where car drivers failed to judge the width of their vehicles with sufficient accuracy.

But why are cars getting wider? Surely car designers and engineers see the same littered road sides themselves, get stuck in the same jams and find it tricky to park inside the white paint lines in a multi-storey car park?

And it’s not just the gargantuan Sport Utilities that are guilty here. It’s a rare event to go on a car launch where the replacement model is the same length or shorter than its predecessor, and almost unknown that a car gets narrower.

Clearly crash safety has put paid to elegant, narrow yet spacious cars like, for example, Aston Martin’s DB4 (1676mm), BMW’s 2002 (1590mm) or Mercedes-Benz’s 190 (1678mm). Ian Minards, former Aston Martin chief engineer, once described the fearsome American pylon test as ‘effectively picking the car up and throwing it against a telegraph pole’.

In these laboratory tests, engineers and designers have got to get the car’s passengers slowed in a controlled manner with a largely intact cabin and that means space for deceleration and side airbags, which means more width. And even though spinning your ride into a telegraph pole is a predominately American accident, if you want to sell in world markets, side impact standards are a default requirement. And it isn’t just the side impact to blame here. As cars get longer to take in frontal crash structures, designers are forced to widen the bodies to keep the car’s proportions.

So that’s some of the width, but surely not all of it? Another reason is that we are getting bigger (as David Twohig pointed out recently). Walk round any very old building and you’ll know all about this as beams and door openings make painful contact with your head. Much improved childhood nutrition is responsible for increases in height and frame and although that process is slowing, it’s not stopping.

Taking figures for average adults between 1975 and 2014, a study by the Norwegian University of Science and Technology showed that the average global adult in 2014 was 14 per cent heavier, 1.3 per cent taller (and had a 6.1 per cent higher energy demand since you asked).

Space isn’t the final frontier, it’s the cutting edge of marketing a new car. Legendary Ford engineer Richard Parry-Jones explained that the original 1998 Focus was much wider than its Escort predecessor because human frames were getting bigger, yet while that Mk1 Focus was 1700mm wide, the latest model is 1844mm across, 144mm wider.

There’s also the matter of tyre sizes. Big wheels look good, think designers and marketeers, and more power and weight also demand additional footprint. So that new Peugeot 308 model rides on 18-inch rims, where its predecessor ran on 17s (in fact the engineering team were proud that they’d made the previous GTI model handle and grip on these smaller rims). To keep the tyre proportions, they’ve been widened, too and that means deeper wheel arches to contain them, which means more width.

It’s a trick that’s also played by engineering departments. To get better response and more grip, they’ll increase the track and add wider tyres which means bigger arches. Never mind that outside of the widest roads or race tracks virtually no-one will be able to exploit this grip and besides, as Andrew Frankel recently explained, good handling isn’t actually about grip, but chassis balance. And less width means a more agile car. I’d challenge anyone to come up with a more wieldy road car than a Den Motorsport Mk2 Escort which is 1570mm wide.

So, are battery cars going to help to reduce the spiral of increasing width? On the current evidence it seems unlikely. The industry appears to have plumped for the battery-in-the-floor design pioneered by Tesla and given the current energy density of lithium-ion cells and the need to give ever more power and range, that means bigger and wider cars to stuff more cells into the wheelbase and bigger wheels and tyres to support their weight; Porsche’s Taycan, for instance, is 1966mm wide, while Mercedes-Benz’s EQS is 1926mm across.

Structural batteries can help to spread the cells throughout the car’s body, but the use of carbon fibre structures in which to house these shaped cells tends to raise the lifetime environmental impact of the vehicle and as we are seeing from the latest BMW iX and i4 battery electric vehicles, carbon fibre use is being scaled back.

Enjoy the relatively narrow cars while you can, because like the average British figure, they ain’t getting any thinner.