What is it?
 
It's a new compact MPV and the first in a family of five transverse-engine, front-wheel drive, compact Mercs. Others will include a new A-class due next year, and probably a mini-CLS-like coupé, a seven-seat larger MPV and a small SUV. The 'twin-floor' architecture of the previous A- and B-class cars has gone, and the next A-class will be a regular five-door hatchback – the first-ever such car from Mercedes-Benz. Hybrid and electric B-classes are in the plan.
 
Technical highlights
 
This is a properly new car, with a new platform using four-link rear suspension and a rack-mounted motor (like the VW Golf family and the Alfa Giulietta) for its electric power steering. The engines are also new; they are a 1.8-litre turbodiesel of 109bhp (B180 CDI) or 136bhp (B200 CDI), and a 1.6-litre petrol engine with on-demand ancillaries (water pump, oil pump), direct injection and turbocharging. Two flavours here: the B180 has 122bhp, the B200 156bhp.
 
Unbelievably, the aerodynamic drag coefficient is just 0.26 despite the bluff-looking shape. Technogizmology includes a standard-fit system which warns when you're closing too quickly on a vehicle in front and adds the right amount of effort to your subsequent braking to avoid, if possible, a crunch. The usual plethora of idiot-aids is optional: driver alert, lane keeping, blind-spot warning, speed-limit display and suchlike.
 
What's it like to drive?
 
The old B-class's high floor forced your legs almost straight out in front, so you felt like you were driving a sports car two feet off the ground. This one has a normal driving position and is the better for it. The cabin quality is properly Benz-like, with real love having gone into the fairings for the interior door handles and a quintet of lovely metal facia vents formed of mirror-image, point-to-point vees. At centre stage is an iPad-like screen for information and media functions.
 
The petrol-fuelled B200 is the B-class most likely to pass through the evo filter, and it makes a surprisingly strong case for itself. The engine is strong, revvy and smooth, with a crisp edge to its note and plenty of low-end thrust. The six-speed gearbox – an alert but jerk-free, seven-speed double-clutcher is optional – has an easy, accurate, satisfying shift, the brakes are firm and progressive.
 
Sport specification is obligatory with the B200 (SE is the lesser-model alternative), which means firmer, 15mm-lower suspension, 'direct' steering whose variable ratio speeds the off-centre response, and 18in wheels. These make knobblier an otherwise smooth, fluent, well-controlled ride while adding little to the impressive front-end grip (there's an understeer-inhibiting system which brakes the inside front wheel) and the precise, easily-metered agility.
 
You can have an unexpectedly good time in this car because its dynamics hang together so well, but it's better on the 17in wheels offered in other markets. Unless you have to be a fashion victim, it's worth specifying these. All of this bodes well for future fast versions of the A-class, which could be a dark horse in the making.
 
How does it compare?
 
As with the previous B-class, this one is £2-3K more expensive than its obvious, but more humbly-badged, rivals. It could be that the three-pointed star justifies the extra cost, and there's certainly a sense of quality here. It's more engaging to drive than a Golf Plus and it's more useful than a CitroΫn DS4, but a Ford C-Max plays the thrills-versus-finance card better than all of them.
 
Anything else I need to know?
 
MPV stuff, mainly. There's a slideable rear-seat option, but in no B-class do the rear-seat bases move out of the way to let the folded backrests sit low. So the load platform is high, and it slopes slightly uphill. However, there's unusually generous space for rear passengers' feet under the front seats, so they can stretch out. UK sales start next March, with the B200 Sport priced at £23,955 for the manual and £25,405 for the DCT.