As concepts go, few things sound more incorrect than a diesel-powered Alfa Romeo. Yet it was Alfa Romeo which ushered in the technology behind most modern turbodiesels when it launched the 156 JTD seven years ago.
Today almost all diesel cars use common-rail systems, where fuel is delivered from a common fuel rail and injected into the cylinders at massive pressure. But now Alfa Romeo, together with parent company Fiat, is pushing through the next generation of common-rail Multijet diesel engines.
The 147 JTD 16v employs this technology: unlike normal common-rail engines, the Multijet squirts several small shots of fuel into the cylinders to promote better combustion.
The original 1.9-litre block is retained but undergoes some serious surgery, gaining four valves per cylinder, an extra camshaft and new intake and exhaust manifolds, while injector pressure rises from 1300 to 1400 bar. The resulting figures – 138bhp at 4000rpm and 225lb ft at 2000rpm – show a useful improvement over the single-cam JTD’s 113bhp and 203lb ft.
That’s more twist than the 247bhp 147 GTA produces; although it’s more relevant to point out that it also out-torques the 184lb ft of the cheaper Ford Focus TDCi and similarly priced Audi A3 1.9TDi.