Road Test: Mercedes-Benz M Class ML63 AMG 5dr Auto

You might consider the words ‘high performance' and ‘SUV' to be as incompatible as the words ‘elephant' and ‘ballet'. And, in any rational world, you'd be right. As a rapid way to transport loads of baggage, in all conditions other than off-road, a 4WD estate car makes several galaxies more sense than any of the current crop of steroidal-pumped SUVs. But AMG asks you to suspend your disbelief for a while longer, because its new ML63 AMG is here to try to persuade you otherwise.

As the brand that started the whole hopped-up, high-rise mud-plugger market back in 1999, Mercedes's tuning arm's first vehicle to plough the super-SUV furrow was the ML55 AMG. Although it was quick in a locomotive sort of way, it was also one of the most unreliable cars of all time, devouring brake discs like digestive biscuits and generally falling to pieces if you even looked at it harshly. I know - I had one.

The second act in the ML AMG saga was the much-better ML63 AMG, which had the decency to hang together for more than five minutes, look and handle more dynamically and could, in a straight line, completely fill the rearview mirror of most mid-range sports cars. So, a lot less to loathe, and loads more to like.

For this third attempt, the updating process has been more subtle, but no less impactful. Starting with the engine, the raucous normally aspirated 6.2-litre V8 has been replaced by a retuned version of the less ferocious but way more efficient M157 twin-turbo V8 from the CLS AMG. A move that hikes average fuel consumption from the tank and bank-draining single digits to a more acceptable 24mpg. If thrust rather than frugality is your main aim, the optional AMG Performance Package will have those numbers heading back into solitary figures quickly.

The chassis is quieter, more composed and precise due to a number of new additions. Active air suspension with adaptive damping and a fiendishly complicated arrangement called Active Curve System, which compensates for body roll using hydraulics, does an amazing job of keeping all 2.3 tonnes of the ML AMG planted on the road. The 40/60 front/rear power distribution - it's 50/50 on a standard ML - also helps the thing turn quickly. As does the AMG speed-sensitive steering.

The problem is, none of it feels natural. Yes, it goes fast. And, yes, it can corner quicker and flatter than you'd have thought possible. But you're never less than totally aware it's the science beating the physics, not you. Fine, if you don't mind that sort of thing, but have a go in a high-performance estate before you buy one of these. If that doesn't change your mind, here are two more words to conjure with: ‘think' and ‘again'.