Ford has taken an axe to the Fiesta Econetic’s efficiency figures, bringing CO2 emissions down by 8g/km to just 87g/km, and improving the fuel economy by 7.1mpg to an incredible 85.6mpg.

The improvement is brought about by a series of measures including the installation of stop/start for the first time on a Fiesta, as well as revised gear ratios, improved efficiency of the heating system, recouping of the energy produced under braking and upgrades to the 95hp 1.6-litre diesel’s friction and combustion systems. The changes ensure the Fiesta stays in the lowest BIK tax band when the bandings tighten next April.

Available in Edge, Zetec and Titanium trims, the Econetic also retains features of its predecessor including low rolling-resitance tyres, aerodynamic tweaks and a gearchange indicator, although the latter only indicates when it’s more efficient to change up, but not down.

The 1.6 diesel is fine around town, but needs to be worked hard for decent acceleration, due in part to the gear ratios being tailored for economy rather than performance. It’s also not the most peaceful of engines, while economy comes at a price of more than £15k, although a decent RV of 33.0% helps claw some of that back.

Ford Fiesta 1.6 TDCi Econetic Zetec 5dr
P11D price £15,540
Fuel consumption 85.6mpg
CO2 (tax) 87g/km (13%)
BIK 20/40% per month £34/£67
Insurance (1-50) group 12
Boot space min/max 295/979 litres
Top speed/0-62mph 111mph/12.9secs
On sale May 2012
Score 8/10
Verdict Class-leading efficiency
though refinement, price
and performance all suffer
to varying degrees.