Hybrids? Who’d want one? Expensive and over-rated when you compare them to modern ever-so-frugal petrol engines.

Well, that’s the common dismissal of all things hybrid. And it’s true that the list price might in some cases be a little eye-watering, but there is no denying that the hybrid message is getting through.

Take Toyota. They’re celebrating having just sold their six millionth hybrid model. So much for small beer, then? Even in the UK, where such hi-tech engineering is yet to become commonplace, we bought 24,649 Toyota hybrids last year, up from 19,905 the previous year and 17,545 the year before that.

The only way is up. And with ever-improving technology, together with increasingly expensive fuel, one day soon hybrid will be normal and Toyota will be in pole position.

So, what exactly is a hybrid? Essentially, it’s a car with a comb-ination of two energy sources, usually petrol and electric. There are petrol-only cars, of course, and a few electric vehicles (EVs).

But electric-only vehicles have to get to a charger before they run out, leading to ‘range anxiety’. They are very cheap to run but obviously the limited range (100 miles or so) makes them impractical for many.

So, hybrids, which use electric power but which have the back-up of a conventional engine, can be better for the real world.

Tested here is Toyota Yaris Hybrid, which costs from £15,495. The version here is the Icon which is £16,495. Not cheap for a hatch, but it is a very well-regarded car, known for its quality, style and reliability.

Yaris Hybrid is one of 24 hybrid cars and one plug-in hybrid in 80 countries. In the UK, home to production of the hybrid versions of Auris and Auris Touring Sports, the range extends to ten Toyota and Lexus hybrids, plus Prius plug-in. Toyota will launch 15 more hybrids over the next two years. And the company claims that, as of the end of 2013, Toyota hybrids reduced the amount of CO2 entering the atmosphere by 41 million tonnes. On the same basis, it also estimates its hybrids have saved around 15,000 million litres of petrol. Wow. Impressive claims!

So, how does Yaris Hybrid measure up? Well, its performance is conventional, managing 0 to 60mph in 11.8 seconds. It uses a CVT (continuously variable transmission) which is a stepless automatic. It is, of course, smooth and perfect around town but not quite so good on motorways, but still quiet and responsive. The economy figures are excellent: more than 83mpg around town and more than 76mpg on a run.

Unlike some hi-tech models (Prius and Honda’s Insight) which look very different to mainstream cars, only a badge indicates that this is a hybrid.

But the biggest change is arguably the most beneficial: due to the extra cooling demands of the hybrid system there is a larger grille at the front and the bumper has been restyled to accommodate it. It gives Yaris Hybrid more presence than the standard car. The Yaris Hybrid uses essentially the same setup as the Auris Hybrid but with the four-cylinder petrol engine downsized to a more suitable 1.5 litres. Sandwiched into the Yaris’s underbody is the petrol engine, inverter, electric motor and battery pack. Equipment onboard includes stability control, dual-zone climate control, leather trim, alloy wheels and no end of airbags (front, side and, believe it or not, knee bags). A Touch & Go system (an extra £640) adds a commendable satellite navigation system, DAB radio, Bluetooth, USB ports and rear-view camera.

All in all, a great way to be green and discreet.