LOTS of new cars have a little indicator on the dash suggesting it's time to change up a gear. The idea is to save fuel, of course.
Trouble is, most of the time following the eco prompt gives you a car that would fail the skin/rice pudding test, so you soon don't bother taking the indicator's advice.
Not so with the car driven here; it uses the most powerful diesel available in the new Vauxhall Astra and was soon telling me to select fourth gear up the sorts of hill you'd be taking frequent rests if out for a walk.
Back on the level, a firm push of the accelerator brought the sort of proper shove in the back that was once the domain of something with a GT badge.
All this urge, and from a point where a rev counter needle is hardly awake, is helped by the diesel engine using two turbochargers, one starting things off and the other taking over at higher revs.
It works a treat, producing an engine that never shouts, even though it's not one of the 'Whisper' diesels Vauxhall is so proud of in less potent versions.
The news gets better still. After more than 400 miles - many of them enjoying the solid punch of the car's engine - the trip computer showed a very healthy 60.7mpg.
That makes this particular version of the Astra about the most beguiling mix of power and parsimony you can buy. You can tilt the table towards economy a little more and save £605 by ordering your Astra with a less powerful diesel, but I'd be tempted not to.
This new UK-built Astra is usefully lighter than the old version, which will help on the economy front. It is also a little shorter but the designers have managed to find a bit more room in the rear seats.
The range kicks off at £15,915 for a car with a 1.4-litre petrol engine and tops out with the £24,101 Elite with the less power (136 horsepower) diesel but with all the goodies and automatic transmission.
Astras might be too closely linked to the image of a 'rep's car' for their own good, but peel off the badge and this could convincingly carry a much posher name on the back.
The smart exterior is more than matched by a cabin that is a bit black-all-over but which is obviously well put together. It is also neatly and logically set out, with enough switches retained for things like heating and ventilation that you don't spend ages prodding at a touch screen.
This version's performance is backed up by a ride that turns a bit too tough on poorer roads, perhaps down to low profile tyres on 17-inch alloy wheels - which also kick up a roar on coarser surfaces.
Smoother roads turn the Astra into a convincing and hushed long distance machine, capable of loping counties at a single bound and using very little diesel while doing so.
Standard kit on this SRi model includes an easy to use satellite navigation system, cruise control and a driving assistance pack that gets jumpy if you approach traffic without braking promptly enough.
It doesn't, but should, include parking sensors to make reversing into a supermarket bay less of a guessing game. They're available for a hefty £460 and ought to be standard.