What is it?There are times when Audi, to great fanfare, brings out an all-new car and you look at it or even drive it and go new, huh, really? This is not one of those times.The second generation Q3's body is bigger by 10cm, better-proportioned and a lot roomier than before. Besides, since the first Q3 launched, the whole 'compact premium crossover class' has become very much a thing, and has coalesced around a fairly fixed size band and mechanical layout. See the BMW X1, Volvo XC40, Jaguar E-Pace. Incoming, and funnelled into the same template, are the Lexus UX and second generations of the Range Rover Evoque and Mercedes GLA. Hardly any of those existed when the first Q3 was born.For the new Q3, another variation of Audi's scary-goth LED eye make-up sits outboard of a socking great eight-sided grille frame and more angular front 'intakes' (most are actually blanks). The body's metalwork is fashioned into a set of sharp creases, amped up further by a dose of Ur-Quattro in the front and rear wings. It's German, so of course the base wheels, in this case 18s, look weedy and you'll want to step up an inch.Inside, the infotainment moves to a touchscreen. No more dials for the driver\: every model has the 'Virtual Cockpit' TFT screen. Under the body, another sea-change. To absolutely nobody's surprise, it now uses the VW Group's MQB platform. It's the same wheelbase as the VW Tiguan. Top Gear asked the project chief if there were any fundamental chassis differences between the two. He was candid. None. Well... the wheels.That said, the Audi feels surprisingly more nimble than the VW, on account of its different set-up\: springs, dampers, bushes and so on. And also because you sit 4cm lower in the Audi. It launches with more petrol engines than diesel. In fact just one diesel, the familiar 2.0 TDI with 150bhp. The petrols are the 1.5-litre 150bhp and a 2.0 with power of 190 or 230bhp.All the 2.0-litre ones have quattro. But many Q3s will be used entirely for gentle suburban bimbling, as opposed to actual sport-utiliting (look, it's a word 'cos we say it's a word). So, for obvious reasons the base petrol engine comes with front-drive.They use Audi's new engine-output badges. So the lower-power engines are called 35 TDI and 35 TFSI, and the 190bhp petrol is 40 TFSI, and the 230bhp petrol is 45 TFSI. Audi provided us with a page-long document laying out this new scheme. But nowhere did it say how they came up with those numbers, or more saliently, why.What is it like on the road?The 150bhp petrol deactivates two cylinders for saving fuel when you're not trying too hard. This is a nice engine in a VW Golf or elsewhere, but here it struggles. Outright performance calls for patience, taking 9.2secs to get to 100kph from zero, but you can forgive that because it's a small engine in a bulky car. More seriously annoying is that it's sullen rather than playful.It's laggy below 3,000rpm and gritty-sounding above, so whatever gear you choose, you wish you were in another. The new seven-speed DCT doesn't help, failing to change smoothly. It's got a petrol particulate filter and meets the latest exhaust standards, and it's also been set up for WLTP fuel measurements. The engineers were overwhelmed by all these new requirements and had to let the actual driving quality slip down the priority list.The 230bhp 2.0 petrol is similarly out of sorts, if less so. It makes the 0-100kph sprint in a brisk 6.3secs. But you'd never guess it's fundamentally a Golf GTI engine. Meanwhile the 2.0 TDI quattro with a manual is quite a nice example of the genre - good at lugging, and not especially rattly. The gearstick moves around slickly, the clutch is smooth and the whole rig is well-mannered even in stop-start traffic.In corners, the front-drive Q3 TFSI rolls little and operates with a nice accuracy. It's fleet of foot. It melds this with a ride that, though taut, isn't harsh or crashy, and copes well with broken town roads. What it does not do is interact; no balancing on the throttle, no steering feel. More fun can be had in the 2.0 Quattro, with stronger engine reactions to amusingly strain the tyres, either under power or when you lift off. Among the many mode settings, the torque proportion to the rear wheels becomes more significant in the 'dynamic' mode.Adaptive damping is optional, or standard on the top trim. It can subtly sharpen up the cornering without despoiling the ride, but it's not transformative. All the Q3s settle decently into a cruise, because that's what German cars do - demolish the autobahn, even if not doing absurdly big speed. The optional driver-assist steering loses the lane markings more often than some others though, so please don't rely on it while you open your sandwiches. There's also an off-road mode, which gives you hill-descent control.On the inside It's all screens now. Not even the base version clings to hardware dials. All models have Audi's Virtual Cockpit TFT screen ahead of the driver. Occasionally it's useful to fill most of this screen with a map, but that does leave you with a nano-sized speedo. A head-up display would compensate as on other Audis, but it's absent here, even as an option.The central screen looks superb. Its got finer resolution than an electron microscope, and is neatly integrated into the dash rather than perched on top. That leaves the air vents sitting high so they'll actually aim at your face. The screen system is cloud-connected as standard, so you get accurate real-time traffic and the like. It uses the same network to set up a wifi hotspot in the car for everyone's devices.But it isn't perfect. Since Audi went to touchscreens, the MMI selector wheel down in the console has been evicted. A pity. It was very well-developed by the end, and good for inputting instructions when the car was bouncing down the road. On the touchscreen, it's hard to hit tiny icons with a jiggling finger, however beautifully rendered they may be. So you might well return to using CarPlay or Android Auto. At least the climate control retains actual knobs.The cabin is good for families, not just because of the wifi hotspot and power outlets, but also because the back is decently roomy. Behind it the boot is hungry-bellied. The rear seats slide too. Makes sense - when you need lots of boot because you've got to deal with a push-chair, your kids won't need legroom so you can slide them forward. When they grow ganglier, pack more lightly and slide it back.The trim and upholstery materials can be had in some outrÃ© colours and textures. But some of the cabin plastics are off Audi's usual form. Why do they obsess on a soft-touch dash top, which you never actually touch, and yet fit hard scratchy door pulls which insult your fingers every time you get in?VerdictCrossovers this size are pretty much default family cars these days, and even the premium ones can't just airily swerve the banal question of practicality. Sure enough the Q3 does fine on room and versatility. And it's well-equipped, and even reasonably generous in its pricing. You don't expect that in an Audi. It's competitive in its chassis. Perhaps more agile than most rivals. But still a little unengaging to steer, which is situation normal for an Audi. Rivals, bar the Jagaur E-Pace, have the same trouble. Still, you can usually trust Audi to do a superb infotainment interface, unimpeachable cabin quality, and refined powertrains. To a greater or lesser extent the Q3 has fumbled all those three.