In this current era of downsizing, electrification, and cost-cutting, it’s rare for the most interesting point about a new car to be the engine it’s packing under the bonnet. Sure, there’s the odd exception – the LT4-powered Chevrolet Camaro ZL1 we reviewed last year, for instance – but they’re few and far between.
This big behemoth you see here, however, the BMW X7, is one such exception. While when I took a look at the entry-level xDrive30d variant last year I was remarkably impressed by the car itself, its engine, a 3.0-litre straight-six single-turbo diesel, while a quiet and confident-enough operator, is a bit same-same when you really think about it.
The same can’t be said for the M50d here, however, as the engine in this is far from your everyday diesel, or your everyday performance SUV engine, but given it’s a diesel bearing an M badge, it’s hardly ordinary to begin with.
Let’s get it out of the way upfront – while the M50d features the same 3.0-litre diesel engine as the entry-level model at its core, BMW’s M division has strapped four turbochargers to it. No, that’s not a misprint – this is a quad-turbo seven-seat family SUV. A Bugatti Chiron for people with kids, if you will.
Producing a whopping 294kW and 760Nm, which is sent through an eight-speed automatic transmission to all four wheels, it’s enough to get the 2.5-tonne X7 from 0-100km/h in just 5.4 seconds. So just a bit quicker than your average diesel, then.
At the risk of sounding as though I’m describing a stand-up comedy show and not a car’s performance, the best way to describe the feel of this thing as hilarious and hysterical.
As the quad-turbo oiler spools up, it lets out a deep bellow as it delivers all of its torque at just 2000rpm with a sledgehammer blow. Getting it off the line isn’t especially thrilling as there’s to much turbo-lag – as on full-throttle starts, it bypasses its two lower-pressure turbos used during normal driving to instead spool up the two larger ones immediately for full power – and too much weight for it to feel immediate in any way, but the progressiveness of how it builds up speed is what is truly thrilling.
Once you feel its full force kick in, it just seems to keep going and going, never feeling breathless at higher speeds, although its hard to imagine it would with those big turbos force-feeding an indicated 45psi of extra air. When it comes to overtaking then, a lack of grunt is something you’ll never have to worry about, yet because it’s a diesel, fuel economy won’t really be of concern when you’re lead-footing it either, as over the course of 740km with it fuel consumption was indicated at 10.5L/100km, which is very impressive given its size.
You simply can’t help but laugh at how fast it is, as it simply has no right to be given its mammoth size, and nor does it have any right to handle as well as it does, either. I’m not going to say it feels anything like a Toyota Supra – although both are actually based on the same BMW Cluster Architecture platform – but thanks to its impressive five-position air suspension system and variable ratio steering, it feels far tighter than you’d expect a seven-seater to ever feel.
But when you calm it down, take it out of Sport Plus and put it back into Comfort, its personality totally changes. The growling diesel’s power delivery smoothens out, the throttle and steering feel more relaxed, its ride gets as pillowy soft as that of the 30d despite the M50d’s larger 22-inch wheels, and you begin to appreciate that this isn’t just a performance SUV, but a truly luxurious one as well.
While all is largely the same as the entry-level X7 on the inside, with the same shockingly roomy interior in which even taller folks will be more than comfortable in the third row, the same array of high-quality leather throughout the cabin, and plenty of features including five-zone climate control and heated seats for all rows, there are a few extras to elevate the M50d to the next level.
The front seats offer even more adjustment for the side bolsters and your shoulders, along with ventilation and massaging functions, there’s a smattering of bling in the form of a crystal shift knob, start button, iDrive controller, and volume knob, and the sunroof has been embedded with little LEDs that correspond to the colour of the ambient lighting to make it look like there’s a sky full of stars above you at night.
Of course, the standard current-gen BMW features are all on display here as well, including the fantastic new iteration of iDrive introduced last year with wireless Apple CarPlay, a crystal-clear digital instrument cluster with reverse tachometer and a font specific to M-tweaked models, and a mini screen for the front climate controls which not only have individual temperatures on each side but individual fan speeds as well.
Being a big, practical family car, it has some family-friendly features, too, such as the automatic split-folding tailgate, and automatic power folding seats in the second and third rows, all of which can be deployed or stowed away at the push of just one button to open its boot space up from 326L with all in place, to 2120L with all folded flat.
Controversially, I’m even going to say that I like how it looks, and always have liked the way that it looks. Yes the grille is a whopper – or, at least, large enough to cook a dozen on – but I think it suits this unashamedly big and boxy beast.
Now, of course, a big car with big power like this unsurprisingly has a big price tag – $171,900 before options and on-roads – but that, perhaps surprisingly, isn’t the biggest thing preventing you from getting one for yourself.
Production shortages relating to the bespoke turbochargers fitted to this quad-turbo diesel mill mean that getting an X7 or the smaller X5 with this engine is a very hard – nay, nearly impossible ask right now. A shame, really, that one of the most unique performance SUVs out there right now is let down by its uniqueness, although it’s about the only thing that lets this fantastic machine down.
Thankfully, if a fast X7 is what you’re after, and you don’t mind footing the heftier running costs of petrol rather than diesel power, you can now get the M50i variant with a 4.4-litre twin-turbo V8 which, for just a couple thousand more, deals an even more powerful blow when it comes to its immense power.
When M50d supplies do start to increase again, however, it’s a car worth checking out if you’re after something truly unique. Perhaps the most niche SUV out there – a luxurious yet sporty quad-turbo diesel seven-seater – it’s surprising that such a thing exists, and while I knew it would be fantastic, what is surprising is just how fantastic it truly is.
2020 BMW X7 M50d List Price: $171,900
Pros: Incredibly torquey and characterful quad-turbo oiler, incredibly well-equipped and luxurious inside, well-balanced ride thanks to the air suspension, feels faster and tighter than it has any right too
Cons: Divisive looks, hard to get your hands on due to production issues
In a nutshell: Not only is the X7 M50d one of the most unique performance SUVs ever made, it’s also one of the very best.
Full Disclosure: The vehicle tested here was provided by BMW Australia for a week with a full tank of fuel. All additional fuel expenses were covered by the author. Additionally, our friends at MPF Detailing gave it a complimentary Express Detail prior to our photoshoot.