The Astra’s body-in-white now weighs 280kg, down from 357kg. It’s only one part of a weight loss regime that means the Astra – like for like, not some kind of fudge where you swap a 2.0 for a 1.6 and a torque converter for a dual-clutch automatic gearbox – is at least 120kg lighter than it was before. Fudge things through downsizing and so on and you can make a new Astra appear 200kg lighter than the old one.
It’s one of those virtuous circles; a lighter body and suspension means wheel sizes are smaller (18in is now the biggest), as are the brakes that sit within them.
There’s still MacPherson struts at the front and a torsion beam with Watt's linkage at the rear, but the front suspension cannot accept the ‘HiPerStrut’, as used by powerful versions such as the previous VXR, and the platform isn’t being asked to underpin a crossover too. It’s leaner and cheaper - shorn of fripperies. In political speak, Vauxhall would have made ‘efficiencies’. From that point of view, it’s a car of our time.
My hunch is that the Astra is significant not just as a new Vauxhall but as the most notable among a new generation of family cars, which will place weight reduction at the top of the agenda. We’ve had the fat early 2000s - the 2008 Audi RS6 that weighed 2145kg and averaged 16mpg in our hands – until it all got a bit silly and now motoring is as austere as the rest of the world.
The Astra has no flat underfloor tray, because it would be too expensive and too heavy. Instead, the underbody itself is flattened and suspension parts are hidden in the kind of thinking that will let a 1.6 Ecoflex diesel emit just 82g/km of CO2 when it arrives.
It hasn’t arrived yet, though. For the moment, we’ve tried a 1.6-litre diesel (to be road tested soon) and a 1.4-litre turbo petrol, which I’m majoring on here. As with the latest Ford Focus, there’s a 1.0 petrol triple, too.
What's it like?
Step inside the Astra and you'll find that interior hasn't suffered with the new attitude.
Materials and their finish are largely good. To my mind, the Astra has the measure of a Focus but not a Volkswagen Golf in terms of perceived material quality. Ditto ergonomically, although Vauxhall’s new central multimedia screen is quite slick. You can also have OnStar, which offers lots of things your smartphone already does and a few it doesn’t.
The driving position is generally good, although a couple of test cars had a rather spongy brake pedal and a vague clutch. And while exterior dimensions have shrunk, inside it hasn’t; rear leg room is up by 3.5cm and the boot is large.
If the Astra is smaller outside and bigger inside and weighs less than before, though, does that mean something has to give? Presumably, yes; there’s reduced material use in general, including soundproofing ones, so the focus has switched to reducing noise at source.
That’s no bad thing; the drag coefficient is just 0.285 (it was 0.325 before), while the new 1.4 turbo petrol engine has been designed with resonance and weight reduction front of mind. Its block alone is 10kg lighter than the old 1.4 Turbo’s.
It’s quiet, then, so road noise, rather than wind or engine noise, is the major source of cabin NVH. More than before? Probably, but it’s hard to tell without a back-to-back test, and a reduction in other noise means the Astra is refined enough.