The Alfa Mito 1.4 Multiair, BMW 320D Efficient Dynamics, Honda CR-Z, Mercedes E200 CDI Blue Efficiency SE and Volkswagen Golf GTD may seem an odd group of cars.
But they all have some key features in common: 0-60mph in under 10 seconds and average fuel consumption above 50mpg.
What makes this fascinating is that the cars' makers have gone about achieving these results in different ways.
The Honda CR-Z is the first sporting hybrid. It's propelled by a 1.5-litre petrol engine that functions in tandem with an electric motor, the two combining to produce 122bhp. Co2 emissions are 117g/km.
BMW's 320d Efficient Dynamics is less technically adventurous, bigger and heavier. Yet the 161bhp diesel scores 109g/km, out-accelerates the Honda and can carry five.
The Mercedes E-class Blue Efficiency produces its 134bhp at a low 2800rpm, and manages 137g/km.
The Golf GTD is perhaps the least radical car here, although its 168bhp 2.0-litre common-rail diesel is one of the best in the business. It hits 139g/km in manual form, but 147g in this DSG version.
Alfa's Mito is also a relatively conventional hot hatch, and has the innovative Multiair engine. Just 1368cc, it produces 133bhp and emits 129g/km of Co2.
In the cars
You sit low in the Honda, and it's spacious up front. But there are restricted views over the shoulder and behind, and the rear seats are useful for luggage only in reality.
The engine's eagerness, the short-throw shift, the sporty driving position and a firm ride all encourage spirited driving, as does the limited roll, plentiful grip and steering that's quicker than the Insight's. The chassis, though, is still disappointingly inert.