The new Mercedes-Benz B-Class

We've never quite understood the Mercedes-Benz B-Class here at Top Gear, except that it's a little bit smashing. Now meet the new one, unveiled today ahead of its world premiere at next month's Frankfurt motor show.

It's a bit longer, a tad wider and a touch lower than before and has been thoroughly, thoroughly re-engineered. In fact, Merc development chief Dr Thomas Weber said: "No model change in the history of Mercedes has seen so many new developments introduced in one fell swoop".

See more pics of the new Mercedes B-Class

It gets a brand new 1.6-litre four-pot petrol engine, dubbed M270, available with 122bhp in the B180 and 156bhp in the B200. There's also a revised version of the four-pot diesel seen in the C and S-Class models: a 1.8-litre with 109bhp (in the B180 CDI) and 136bhp in the B200 CDI.

Two options are offered for your arms, Merc's 7G seven-speed dual clutch auto - a premiere in this model - or a trad' six-speed manual with "low shift forces". The chassis gets ESP, a lowered centre of gravity and a new four-link rear axle, all of which make it "fantastically agile". You can option some sports suspension that lowers the car by 20mm and adds sports dampers with amplitude dependent damping. The previous generation was thoroughly delectable to drive, so there are good sign for this new one...

As you can see, it gets Merc's new corporate face, replete with those tasty new lights and shouty grille, pronounced wheel arches, new side skirts and even a roof spoiler. And despite being nearly 5cm lower than its predecessor, Merc claims there's better headroom and, after listening to customers, has installed a more upright seating position. The legroom of 976mm eclipses even its executive S-Class and E-Class siblings.

There's the option of rearranging the interior with the Easy-Vario-Plus system, while high quality materials and precision workmanship - a Top Gear gripe with the old B-Class - have been used inside. There's even a TFT colour display to play with.

The new Bee gets a dizzying complement of Santa's little helpers, including blind spot assist, attention assist, parking assist, a reverse camera and hill hold function. There's also the option of the COMAND multimedia system offering Internet access on the go so you can update your MyFace page and tell your Internet friends what you had for breakfast.

The 2011 Frankfurt motor show

It'll hit UK shelves in March 2012 with prices to be confirmed, but the current B-Class starts at £19,640. Interested in this premium, sporty mini-MPV?