If all diesel engines were created equal and could be measured solely on their figures, the 148bhp variant found in the Volvo V40 D3 would appear to be perfectly suited to the 21st century business of propelling a hatchback around promptly and economically.
A sub-9.0sec 0-60mph time and a 45.9mpg overall economy figure attest to that. The five-cylinder unit likes to warble but, at 68dB at 70mph, it is not intrusive or unpleasant.
But there are issues, chiefly with the way the V40 delivers its power. The D3 may develop all of its 258lb ft of torque at just 1500rpm, but it idles at 720rpm and the six-speed manual gearbox has a habit of repeatedly stumbling on the 780rpm of lethargy in between. Typically, this occurs when ambling slowly around residential street corners in second or third gear.
An impatient driver (or, indeed, anyone concerned with forward motion) will attempt to remedy the chronic lag with a more aggressive stab of the throttle, leading to a sudden rush of energy as the engine – or, more precisely, its turbocharger – catches up with your intentions. Spend too much time turning in and out of tight junctions and the D3’s driving experience comes worryingly close to tiresome.