A 1.0-litre three-cylinder version of the Ford Fiesta Zetec, equipped with a six-speed twin-clutch “Powershift” automatic gearbox, arrived in the Autocar car park a couple of days ago, generating instant interest.

We’ve been keen to try this combination ever since it was first suggested: twin-clutch gearboxes play well here, and we were curious to see whether the ubiquitous 1.0-litre turbo triple engine — which must surely be heading for immortality already in the Ford engines Hall of Fame — could cut it when attached to a modern self-shifter.

So impressed was I after the first few miles that I tweeted about the car’s excellence, half-knowing what would happen — and it duly did. In came the usual volley of complaints from respondents convinced (correctly) that the Powershift Fiesta was never going to deliver on its official fuel figures: 42.8mpg urban, 72.4mph extra-urban and 57.7mg combined. 

The inference, as usual, was that this was a deception being visited on the gullible and financially oppressed public by the Big Bad manufacturer, who probably lies about everything.

Which, of course, is nothing like the truth. I do wonder, sometimes, how consumers can be quite so dimwitted. Perhaps it’s because they’re so used to protection that rational thoughts no longer need be on the agenda. 

Here’s the truth. 'Government' fuel figures are required to be published by manufacturers. It’s the law. If car makers didn’t publish them – and all derive them on exactly the same unrealistic basis as everyone else – they wouldn’t be allowed to sell the cars. As well as anyone else, manufacturers know their only use is as 'constants' and yearn for the day – which is slowly approaching – that a better system is designed.

As I sit here, the Powershift Fiesta’s trip computer (accurate enough for this exercise) reads 35-point-something, the average consumption for about 80 miles of driving in my hands, consisting of two trips to central London (44 miles) plus some cavortings on nearby motorways while I investigated flat-chat acceleration and various full-throttle shift points. 

I know if I make a bit of an effort later today, I’ll get it into the 50s, after which real-world consumption will settle into the mid-to-late 40s. Which I reckon is just fine for a zesty little self-shifting car with a 112mph top speed, and 0-60mph acceleration in around 10.8 seconds.