Models
5dr SUV (M40d)
History
BMW's famous M motorsport division made a full Motorsport-tuned version of their G01-series X3 mid-sized SUV. This wasn't it. This X3 M40d variant was instead, like its M40i petrol counterpart, an uber-fast and potentially rather desirable performance version of the standard model, first launched in 2018, then three years on updated with the Munich maker's efficient 48V mild hybrid tech and a series of visual, cabin and media updates.
As the 'd' in the model name suggests, it fuels from the black pump. If you don't naturally equate the word 'performance' with 'diesel', then you'll need a mental reset here because the M40d really is very fast indeed, yet it's capable of reasonably frugal returns, even if you give in to the urge of regularly thrashing its 340hp 3.0-litre straight six engine about. In the 2018-2024 period, only Audi's SQ5 TDI could rival this combination in this class. But this M40d always claimed to be a sharper driver's device. The car sold until the fourth generation G45-era MK4 X3 design arrived in mid-2024.
What You Get
In keeping with its segment rivals, the exterior looks here are uber-subtle. To the point where many would mistake this car for an ordinary X3 with M Sport trim. Informed loyalist of Munich marque will of course know different, noticing the larger exhausts and the bespoke badging on the tailgate. Other smart touches include bespoke 20-inch M light alloy Double spoke M wheels finished in bicolour Orbit Grey. And a Cerium Grey with black finish for the kidney grille, plus bespoke calipers for the M Sport braking system and Cerium Grey mirror caps.
Inside, apart from a smattering of extra M badges and anthracite headlining, the emphasis on subtlety continues, though some original buyers lifted the cabin with options like red leather upholstery. The twin-screened 'BMW Live Cockpit Professional' set-up became standard with 2020 facelifted models. That brought a 12.3-inch instrument binnacle display and a 12.3 'Control Display' for the centre of the dash. Plus you get the 'BMW Intelligent Personal Assistant', a voice control system responding to the command 'Hey BMW'. 'Apple CarPlay'/'Android Auto' smartphone-mirroring is now (at last) standard. And that upgraded infotainment set-up updates itself with 'over-the-air' upgrades, so you'll get into your X3 one morning and find it able to do something it couldn't do the day before.
There's plenty of headroom in the back and comfortable space for a couple of adults. Plus you get a decently shaped by 550-litre boot which can be extended to 1,600-litres by folding the 40:20:40-split rear bench.
What to Look For
Our owner survey revealed many satisfied users of this 'G01'-series X3 model, but inevitably, there were a few issues reported. The six cylinder diesel engine in the M40d is also pretty reliable, but we have come across issues with coolant and oil loss, failing gaskets and VANOS solenoid failure.
As usual with BMW diesels, the main thing we'd check for is for diesel particulate filter problems for diesel cars which haven't ventured onto the highway very frequently. The DPF has to be up to temperature before it can regenerate. Obviously, a fully-stamped service history is vital. This car uses complex engines and only regular and appropriate maintenance will see them go the distance. Otherwise, it's just the usual things. Insist on a fully stamped-up service record and check the alloys for scratches and scuffs.
Replacement Parts
(approx prices based on a 2021 M40d ex VAT -autodoc.co.uk) An air filter costs in the £8 to £18 bracket. An oil filter costs around £6-£56. Fuel filter prices vary widely - you can pay from £3 upwards, depending on brand. Cabin filters sit mainly in the £8-£55 bracket. Front brake pads sit in the £39-£72 bracket for a set; for rears, it's around £18-£72. Brake discs can be very expensive; fronts from £88-£214; rear discs tended to be in the £49-£196 bracket.
On the Road
By 2018, we'd seen this M40d model's 'B57' M Performance twin turbo 3.0-litre straight six cylinder engine before in various black pump BMWs mated, as here, to xDrive 4WD and an 8-speed paddleshift auto transmission: there's lots to like about it. Power output is a healthy 340hp and there's a healthy 700Nm of torque that you can access from as low as 1,750rpm, so when you put your right foot down, this car simply storms towards the horizon. The 62mph from rest sprint occupies just 4.9s en route to a top speed that has to be artificially limited to 155mph.
You get all of this to the accompaniment of a crisp, muscular soundtrack that's emphasised if you select the provided 'Sport' mode. Lowered M Sport suspension with adaptive damping firms up body roll. Plus M Performance-specific variable ratio steering sharpens corner turn-in, while beefier M Sport brakes enhance stopping power. The alternative M40i petrol variant also uses a 3.0-litre six cylinder engine, that one putting out 360hp, and replicates this car's performance figures exactly.
Both variants require you to accept a fairly firm standard of ride, but you can ease things by playing with the settings of the standard M Adaptive Suspension. The steering isn't quite as sharp and feelsome as we'd hoped it might be and there's a bit more body roll than you might hope for through the turns, but the M Sport Differential means that cornering traction is impressive. Overall though, this is a very complete package.