What is it?
Not so long ago, if you wanted an everyday car with good performance, excellent fuel economy and even better ergonomics, you bought a turbodiesel Volkswagen Golf.
British roads overflowed with these cars, whose relative dullness, it seemed at the time, was the reasonable price to pay for vice-free motoring in many other respects.
But we all know what happened next, and lately the pick of the Golf’s engine line-up has been the 1.5-litre TSI – a smooth-spinning, downsized petrol that for the eighth-generation car has also been fitted with 48V mild-hybrid tech.
It’s unlikely any diesel-propelled Golf will ever again enjoy such popularity, but the Mk8 version is nevertheless here and, according to Volkswagen’s engineers, TDI power is now even cleaner than the equivalent petrol model.
That’s because a new ‘twin-dosing’ system hits exhaust gases with AdBlue upstream of not one but two selective catalytic reduction (SCR) sites that together act on the gases over a broad temperature range to cut nitrogen oxide concentrations by 80% compared with the old model.
It all sounds quite heavy duty, but it makes the latest diesel Golf exceptionally clean too. Of course, this car also needs to bring owners the more tangible benefit of sipping fuel in religiously frugal fashion. Volkswagen hasn’t released official numbers yet but, on the basis that fuel consumption is said to be 17% better than the outgoing TDI engine, the combined economy figure should better 60mpg by WLTP standards.