This is brilliant engineering. By sweating every detail, Toyota has cut the weight, size and cost of its full hybrid system so it can fit into a Yaris without losing any space (not even in the boot), and the price just about matches a VW Polo Bluemotion.
It's a great little town car. The silence of a petrol hybrid in traffic is a boon, and the CVT eases you along nicely. Even at middling acceleration, it doesn't set the engine revving in the old CVT spin-dryer manner. That only happens when you really floor it. Like any Yaris, it's nimble and tiny on the outside, too.
Trouble is, if you're the sort of person who just mooches around town, you aren't doing many miles a year. So fuel isn't actually a big cost, not compared with buying and insuring and parking the thing. The fact that it can stretch a gallon, according to the official urban figures, 20 per cent further than the Bluemotion seems a bit academic.
And, as soon as you get out of town, you're in a Yaris. That means it feels tinny and sluggish, and a lot less fun, compared with the eco versions of the Polo, 208, Fiesta and so on.
1497cc, 4cyl plus hybrid, FWD, 98bhp total, 80.7mpg, 79g/km CO2, 0-62mph in 11.8secs, 103mph, 1150kg
Unjustifiable on cost grounds, but handy and quiet slipping through urban gridlock. Don't go beyond town.