Road Test: Audi A3 1.6 TDI 2dr

An odd thing this, and one that a few years ago no one would have considered: a small, sporty, diesel cabriolet. Back then, a soft-top with a diesel engine was called a tractor, but technology waits for no man. The Audi A3 Cab, with its more compact and efficient 1.6 TDI engine, is walking the walk.

Formerly the preserve of workmanlike estate cars and insipid frugal hatches, today's cleaner and more capable diesels are not only up to powering a posh drop-top with refinement and appropriate performance, but also of doing it with a clear conscience. Here is a car that is at once a luxury good and an economically sensible, environmentally sensitive choice.

Here's how: smaller and lighter than the 1.9-litre lump it replaces, this new TDI makes more sense in a compact car with sporting pretensions. Sharp off the mark and free of excessive understeer, this is as enjoyable a thing to thrash about as it is a useful tool for sitting out motorway miles.

A fractional loss in outright speed to the old 1.9 is traded off against improved economy, with a feasible 65.7mpg claimed in Audi's blurb. And although that 12.2-second trundle to 62mph sounds utterly interminable on paper, the extra torque you get from a diesel equates to some satisfying in-gear grunt.

This is an engine impossible to fault, making a solid case for itself in the unlikeliest of cars.