Part of the purpose of the day was to show off the Driving ECO2nomy (that's economy with CO2 in it) training days that Millbrook offers.
So, with instructors beside us in the passenger seats of the fleet of Vauxhall Astra 1.9 CDTIs, we set off on a sighting lap where our driving style was analysed, dismantled and then reconstructed.
As well as trying to get the best economy, then, we were also trying to show the biggest improvement in economy from run one to run two.
There are lots of tips on how to improve your economy and you can find them all on whatcar.com by clicking here.
Since the test Astras didn't have underinflated tyres, boots full of bricks or roof racks on, the tips we got from our instructors were focussed solely on the driving.
Looking ahead and anticipating the road is crucial. What's the point of accelerating up to 50mph when you can see you'll soon need to slow down for a roundabout. Even out and maintain your speed as much as possible and you'll save plenty.
Being gentle with the throttle and changing gear at the right time is also rather important. Change up too late and you'll be wasting fuel and if you change up too early, then the engine will labour and also burn more fuel that it would otherwise need to.