Opinion: in praise of engineering solutions that keep things simple

When it was new, I had a Toyota Aygo long-term test car. It was as basic as any car of its era could be. But I wasn’t being punished. I chose it. Its simplicity was the essence of its appeal. They offered the air-conditioning option but I turned it down – it was 10 per cent of the price of the entire car. There followed the hottest summer in memory, but there you are. Sometimes you have to suffer for your art.

Now to be clear, the Aygo’s appeal wasn’t because it had had a load of stuff dumped off it. It was the zen philosophy at work in its engineering. The solutions were elegant, and satisfying. All over the car you’d find places where they used one part in place of several, and ideally made that one part do another job too. Most car engineers are inculcated with the impulsion to use off-the-shelf parts, so they just grab a generic bracket and a commodity nut and bolt, and a hook to fix to the bracket. It works, but it’s a bodge. The Aygo’s philosophy was to use instead a self-fastening bracket with an integrated hook. This four-seat hatch was lighter than a Lotus Elise.

Now, you might think the next sentence is a segue that stretches credulity, but bear with me. That Aygo brings to mind Gordon Murray’s T50. He operates by a similar philosophy. F’rinstance, Instead of festooning the outside of his engine and gearbox with hoses, couplings and clips, the coolant runs through passages drilled within the casings. It demanded more thought at the design stage, but it does away with boring ugly leak-prone commodity parts. It’s lighter, and the powertrain looks far more elegant.

All over the car you’d find places where Toyota used one part in place of several

We are now approaching an age where this applies to electronics. Most electric cars have a box called a DC-DC converter. It takes the high voltage from the main battery and drops it to 12V for the one that runs the wipers, stereo, windows and lights. Converting DC isn’t easy – it’s why the mains grid works on AC, so it can use simple coil transformers to reduce the 400kV of the lines on pylons to the 240V that comes out of your socket.

EVs also have a box called an onboard charger, that takes the incoming mains AC and rectifies it and steps it up to the 400V DC to feed the battery. Some of them also have a unit to allow external power takeoff.

The Hyundai Ioniq 5 and Kia EV6 have a better idea. One single box takes care of the DC-DC conversion for the 12V battery. And AC-DC with a step-up for on-board charging. And it has another DC-DC converter because most of the world’s DC rapid chargers still give you 400V but these cars’ battery runs at 800V. A further function gives external 240V AC so you can run your camp kitchen. Integrating everything into that one box does away with a load of messy cabling and cooling pipework.

I’ll never see that simplification, because I won’t be taking the lid off the high-voltage box thank you. And few people will get to see the powertrain of a T50. But lots of folk, every time they open the tailgate of their Aygo, could look in wonder at the cleverness of the one-piece bracket that both mounts the gas strut and hooks up the parcel shelf. Ah, the simple pleasures.