Testing, testing

I hate to break it to anybody already ruing the demise of throttle cables and hydraulic brake lines, but the steering column is the next bit of connective mechanical tissue up for the chop.

- RICHARD LANE

Last week I interrupted our road test of the invigorating new Toyota Aygo X to join some ZF engineers at MIRA. They were in a modified G30 5 Series (with rare cloth seats - how delicious). Fitted to the car was a new steer-by-wire system already serving in Nio’s Chinese-market ET9 but due to appear in at least one senior Mercedes next year. It captures the driver's inputs with a steering wheel actuator, which then informs another mechatronic actuator on the front axle, turning the wheels the desired amount.

In reciprocation, torque sensors on the axle send a signal back to the steering wheel module. There that signal is translated into force by two worm drives that work independently around a single worm wheel, recreating load and, yes, even granular feedback. It’s simple but, as ever, stupidly clever. It’s the second drive, which acts with or against its twin, that’s especially neat.

Asked if I wanted to have a go, I was only too happy to oblige - for journalism, sure, but also for pure petrolhead curiosity. The last car I drove with steer-by-wire was a 2013 Infiniti Q50, which was hardly an exemplar of fizzing feedback.