It was the closest thing I can remember to a completely wasted journey. I set off in my Ford Capri from home in Gloucestershire midway through a Sunday afternoon – when I could instead have been watching an absorbing Six Nations game on TV – in order to position myself in good time for an early Monday morning meeting in London. 

Such was the importance of this meeting that the sacrifice seemed justified, and so it remained until I reached the outskirts of London – to be dead accurate, that raised a bit of the M4 just east of Heathrow airport. 

That was where I learned that (a) not only was this crucial London meeting now no longer happening but (b) I'd have been better off staying at home in the shires because something just as important was now happening there early the following day. 

The only sensible thing to do was to pull a U-turn at the roundabout where the M4 meets London's North Circular road and retrace my route home, spending another two hours and 94 miles getting home. Nothing else made sense. It's normally quite hard to be creative at a brain-stretching time like that, but I'd had an enjoyable trip. 

Traffic had been light and I'd amused myself by driving in an economy-minded manner, cruising between 55mph and 65mph to see if I could maintain the tailwind-assisted power consumption rate of 3.7mpkWh that had initially appeared on the dashboard. 

I had also been able to have some cheery conversations with several friends and family members on the easy-to-operate hands-free phone, so I was in decent spirits when it dawned on me that a reversal of direction made sense. 

For a second my mood threatened to descend into the doldrums, until it occurred to me there might be something to gain from this return leg. How about returning to Gloucestershire as fast as the law would allow adding the 2-3mph of built-in speedo error, and not sparing the right foot when acceleration was needed to maintain pace into what was now a headwind. 

It took 1 hour 58 minutes to reach this point in light traffic: how would journey time and economy differ as I tried hard on the return run? A brief but convenient traffic light stop on a roundabout allowed me to reset the trip and flip the driving mode from Eco to Sport to make the comparison as realistic as possible. 

I accelerated briskly back up the ramp and onto the M4, noting immediately the extra noise of the headwind as I headed west, cruising at the limit. Instead of simply allowing the car to roll I kept it going, eschewing cruise control because I always think I can do a more efficient job of keeping a car going by better anticipating its need for acceleration or braking. This was not a very scientific project. 

I can't be sure the traffic provided the same lack of interference as on the way out when the speed reading was usually 15mph lower; I certainly spent more time in the outside lane. Yet it felt like a pretty good, uncorrupted test. I arrived home in 1 hour 55 minutes, with the consumption readout showing 3.1mpkWh – quite a poor time saving, given that the fuel consumption was 16% poorer. 

A good proportion of the loss, I surmise, was the fault of a breeze the Met Office said averaged 6-8mph, assisting on the way out, impeding on the way back. Two other observations: the seats, in which I'd never spent four hours at a stretch before, were still unimpeachably comfortable. 

There is no doubting this Capri's built-in comfort. Last, having travelled 188 miles from home to London to Heathrow and back, the car's range meter was still promising 92 miles. In half-careful give-and-take driving, I have little doubt that Ford could deliver 280 miles before the 'charge battery' warnings became hysterical – a fine performance.