Potential Fuel Saving: Up to eight per cent, highway

Verdict: Worthwhile … if you’re a leadfoot, or erratic

On 110km/h freeways it’s actually possible to better the cruise control’s economy if you use the throttle extremely sensitively. (We managed a two per cent positive margin without dropping back from the prevailing traffic flow, but you must drive as though the accelerator has a big spike pressing into the sole of your foot.) If you drive assertively, without regard for consumption but reasonably within the speed limit, you will never look like getting close to the economy afforded by cruise control set to the legal limit. Cruise is also a potential licence-saver on long trips, sometimes, but it’s worth noting that with the cruise set to 110km/h the Calais ran up to an indicated 124km/h on one particularly steep descent. Use the cruise to protect your licence if you find your speed creeping up. Fuel saving: the average Australian motorist will save enough fuel to buy around one mug of bad roadhouse flat white every, oh, 19 days. Whoopee!