What is it?
This is as hot as the latest G20-generation 3 Series Touring will get, at least officially.
While BMW has a tyre-shredding M3 saloon in the works, its wagon sibling won’t be getting the same treatment. Munich has decreed that anyone looking for more power in a wagon body must head down the road to Buchloe and ask Alpina for a B3 Touring instead.
If that’s beginning to sound a little conservative, the presence of a single letter should be enough to reassure you: the M340i marks the first time BMW’s junior estate has worn M Performance badging, seven years after the sub-brand was first introduced.
It is now the only six-cylinder model in the current line-up, using an updated version of the familiar 3.0-litre B58 engine that sees power taken up to 369bhp - a significant step up from the 255bhp offered by the four-pot 330i, and enough to enable a 0-62mph sprint in just 4.5 seconds. That’s only 0.1sec slower than the M340i saloon, despite the weight penalty that comes with an estate body style.
it can only be had in rear-biased xDrive all-wheel drive form, and an M Sport locking rear differential comes as standard. The eight-speed automatic gearbox has bespoke ratios, and its suspension has been tuned to give it precision edge over non-M Performance cars. Baby M it may be, but it still has its sights set on the Mercedes-AMG C43 and new, diesel-powered Audi S4 Avant.
We’ve already driven the M340i on the continent, but this is the first time we’ve sampled it in a Touring body, and on UK roads.