If you needed a sign that the booming crossover SUV market has reached full maturity, just look at the number of niche variants splitting the difference between established models. While new entrants like the Mercedes-Benz GLB and the BMW X2 fill alphanumeric gaps, special flavors like these latest M-branded BMW X machines make it clear that the tall-car performance wars are well under way.
In Competition trim, the new BMW X3 M and X4 M produce a whopping 503 horsepower. That just so happens to be within a hair's breadth of both the Alfa Romeo Stelvio Quadrifoglio and exactly the same as the Mercedes-AMG GLC63 S -- either a curious case of cross-brand collusion or the world's greatest coincidence. How does the BMW stack up on the road and on the track? Let's start with a look under the hood.
Source of the power
We've certainly seen and driven the new BMW X3 before, most recently in plug-in, where we found it to be both engaging and efficient. But it's safe to say we've never see it like this. Under the hood, BMW has given one heck of a heart transplant, a 3.0-liter inline six making 473 horsepower and 442 pound-feet of torque. Step up to the Competition model and you get a bonus 30 ponies, plus bigger wheels (21s vs. 20-inchers) and a few other visual upgrades.
This engine is said to be 90% new compared to the seemingly similar lump that appears in the X3 M40i, featuring forged pistons and a specially baffled oil pan BMW says offers nearly all the trackday benefits of a dry-sump system. Despite the dual turbochargers, the engine still revs to a healthy 7,200 rpm, though you won't need to probe the upper limits to make use of that power, with peak torque coming at just 2,600.
That power is routed through an eight-speed automatic transmission before being split front and rear. Though the X3/4 M lack the BMW M5's ability to go full-on rear-wheel-drive, an electronically managed clutch-type center differential handles the torque split, sending a majority to the rear. At the back, an Active M differential ensures both wheels keep turning, but not spinning.
All that makes for a huge upgrade over the base X3/4's 248 hp, and thankfully BMW made some chassis upgrades to match. Additional bracing spans the front strut towers and hangs out beneath the rear sub-frame, while massive, 395mm front brakes are squeezed behind 20- or 21-inch wheels. The Competition rolls on 255/40 front and 265/40 ZR21 rear Michelin Pilot Sport tires.
That's a lot of sticky stuff on the asphalt, and that slight offset size speaks to the extra power going out through the back. It all sounds suitable enough for the track -- at least, until you factor in the weight. The X3M hits the road at around 4,500 pounds, a full 900 more than a BMW M4 and, just for kicks, almost twice the weight of a Mazda MX-5. Good thing that it has nearly three times the power.
On the track
Yes, I know, crossover SUVs seemingly have about as much right to be on the racetrack as I have a right to be on Dancing with the Stars, but just like Emmitt Smith surprised the world on the reality TV circuit, the X3 and X4 M make for better-than-proficient dance partners on a racing circuit.
For my testing, the track was Monticello Motor Club in New York, and for this portion of my testing I was slotted into the coupier-shaped X4 M Competition -- but the overall driving dynamics should apply equally to the boxier X3. And how were those dynamics? Shockingly good.
Monticello is a track with a healthy mix of fast and slow turns, most of which demand patience and a late turn-in. Add in plenty of off-camber stuff, and this is a real test for front-end grip. If your car is suffering from chronic understeer then a day spent here can feel like a very long one indeed.
Call me a pessimist, but it's chronic understeer that I was expecting from the X4 M, and you know what? I was right. Sort of. In its middling Sport setting (which splits the difference between Comfort and Sport Plus), the X4 M did indeed wallow in the corners, front washing away when I got too aggressive and generally feeling proficient but not engaging.
All that changed with a quick double-tap of the M2 button, one of two user-configurable buttons mounted on the left and right stalks of the steering wheel. This bumped most of the car's various drivetrain settings up to Sport Plus, and suddenly things started feeling a whole lot different.
The engine and transmission were immediately far more eager, so too the handling. Able to charge harder both into and out of corners, the X4 M became remarkably poised and balanced. I wouldn't go so far as to call it nimble, but I would call it remarkably good and, yes, surprisingly fun.
That's not to say it was perfect, however. While body roll is kept admirably in check, the high seating position serves only to amplify the motion, leaving me feeling ready to topple out of the (otherwise quite supportive) seats. And then there's the traction control, which was overly pessimistic even with the drivetrain on its most aggressive setting. I have a feeling the X4 M Competition would be a proper hoot with the TC off, but with a polite request to leave the systems enabled, and with the numerous walls at Monticello never more than a brief moment of indiscretion away, I'll have to leave that as an exercise for you, the reader, to discover.
On the road
OK, so BMW's new M-badged crossover SUVs are surprisingly good on the track, but roughly zero percent of all X3 and X4 M owners will ever actually show up at a track-day event. Given that, how these two handle the roads is far more important. This portion of the drive was handled in the BMW X3 M Competition, but again, the experience should be much the same in the X4.
And that experience is a mostly positive one. Though stiff, in comfort mode the X3 M Competition is perfectly livable, harshness only creeping in on broken pavement and railway crossings and the like. Sadly, I didn't have an opportunity to drive a non-Competition spec X3 M, so I can't comment on how much of that can be attributed to the larger, 21-inch wheels, but even they proved perfectly livable.
And the power? 503 horsepower is a lot on a racetrack. On the street it's positively excessive. Mind you, sometimes after a long day at work, excessive is exactly what you need, and the various safety and driver-assistance systems here do a fine job of ensuring that power propels you in the direction you actually want to go.
Those systems include standard active emergency braking with pedestrian detection, while BMW's comprehensive adaptive cruise and lane-keep assist systems are optional. That's a box I'd tick, especially were I planning on road-tripping my SUV anywhere. The comfortable seats are more than up for that task.
The X3 M and X4 M both run BMW's latest iDrive, which is quick and intuitive and offers everything a modern driver could want -- except for the major missing piece of Android Auto. The system is snappy and responsive for the most part, but somehow BMW's gesture control, introduced way back in 2015, hasn't improved a lick. It's still sluggish and actually managed to misinterpret some random gesticulations from my passenger as commands. Gestures are indeed the future, but sadly, we aren't there yet.
Competition and pricing
So, is the X3 or X4 M right for you? Personally, I'd spend my $69,900 on the X3 M and its extra cargo space in the rear. Those who prefer the swoopier styling of the X4 M will pay $73,400. Stepping up to the Competition, with bigger wheels and 30 more ponies, adds a whopping $7,000 to the above prices. That's not exactly a sound return on investment, but then a 473-horsepower SUV isn't much more sensible than one with 503 horses, so don't let me rain on your parade if you're itching to tick that box.
As far as competition goes, again we need look no further than the Mercedes-AMG GLC63 S and the Alfa Romeo Stelvio Quadrifoglio. The former starts at $81,800, while the latter is $79,995, all again within spitting distance. But of those three, only one is manufactured in the US, which may just help to sway some purchasing decisions.
We'll refrain from making a formal recommendation until we're able to give either the X3 or X4 M a proper review. Until then, I have to say I was mighty impressed. The X3 and X4 M Competition offer ridiculous amounts of power and poise in the sort of upright, practical packaging that modern consumers are overwhelmingly saying they want to buy. Maybe this crossover onslaught isn't so bad after all.
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