What's all this about?

It's the totally expected Touring - that's 'estate' - version of the eighth-generation BMW 5 Series. And, just like its four-door relation, for the first time ever in 'Fiver' history, there's an all-electric range of models available under the i5 banner.

Cool, so can you tell me exactly what we're going to get here?

We can from the i5 Touring side of things, yes, as the wagon is going to be heavily electrified in the first waves of its arrival on these shores. In fact, no diesel models are scheduled to come to the UK, not even the former sales heavyweight that is the 520d (and it exists in the world of the 'G61', which is the development code for this Touring generation).

So from launch, the i5 Touring will be available in three trim grades - Sport, M Sport and M Sport Pro - if you buy the regular model, badged up the 'eDrive40'. This, like its saloon relation, has a rear-mounted 340hp/430Nm electric motor, powered by an 81.2kWh lithium-ion battery pack. That gives you both 0-62mph capability in as little as 6.1 seconds, all while delivering up to 348 miles of driving range.

There's then also a Touring version of the mighty i5 M60 xDrive, which kicks out a colossal 601hp and 820Nm from two motors for xDrive AWD. Expect 0-62mph in just 3.9 seconds and a maximum range of 314 miles; think of this as like an M5 Touring, just without an engine. And by that, we don't simply mean an E61 M5 that's having an extensive, remedial S85 rebuild either.

I wasn't going to suggest such a thing. Have you got prices for these?

Yes, the i5 eDrive40 will set you back £69,040 as a Sport - representing the current 'entry-level' for 5 Series Touring ownership - rising to £75,450 as an M Sport and then £78,450 as an M Sport Pro. The M60, meanwhile, is knocking on the door of 100 grand, with an opening figure of £99,090.

Crikey! Not cheap - so what do I do if I want a Five wagon with an engine in it?

You'll need to wait until summer, when a plug-in hybrid version of the car is coming under the name 530e. This has combined outputs of 299hp and 450Nm from its petrol-electric drivetrain, which results in 0-62mph in 6.4 seconds, an all-EV driving range of up to 60 miles, CO₂ as low as 16g/km and fuel economy claimed to be as high as a preposterous 403mpg. There are no prices for that one yet, though.

OK, what else do I need to know?

Well, like any 5 Series, the new Touring will be privy to the latest and greatest of BMW's comfort, assistance and safety technology, plus its high-quality interior fittings. Perhaps the key thing to focus on here is that the 5 Series Touring is bigger in every main, measurable dimension than the G31 it replaces - it's longer, wider, taller, and has a greater wheelbase than the old Mk7 estate. This results in increased practicality and passenger room, while the boot now stands at a minimum 570 litres, rising to 1,700 litres with the rear row of chairs folded away.