In its continued expansion and refinement of segments and classifications it singlehandedly created, BMW has confirmed months worth of rumors and speculation that have indicated an X3 M might be on the horizon. In a recent press release, both the X3 M and co-developed X4 M are mentioned as making their first (camouflaged) public appearance over the weekend of DTM racing taking place at the Nurburgring from September 7-9, 2018.
It’s not uncommon to see photos or video of upcoming model prototypes on and around the ‘Ring, but this time, BMW positioned itself in front of the individuals who make a living by peddling their spy shots and previously unseen footage to automotive media outlets. We don’t have to go into great detail about why it makes sense to develop M versions of the X3 and X4, as both models are proving quite popular in their respective categories, and more and more vehicles in the Sport Activity Vehicle (SAV) and Sport Activity Coupe (SAC) realms, which BMW invented, are taking the place of conventional sedans and wagons (tourings, in BMW speak) as time goes on. The X3 alone, released in its third generation back in 2017, has been leading the way in terms of sales, with BMW devoting significant resources and attention toward bringing additional production facilities online the world over the meet global demand, and while the model used to stand alone in the lineup with the exception of the X5, it’s now flanked by the X1, X2 and X4, which cater to their own specific categories.
But enough about why BMW should develop a fire-breathing, track-ready version of their new and popular SAV and SAC; we’re more interested in what lurks beneath the hood. Observant readers will notice that both the X3 M and X4 M prototypes wear a special vinyl wrap over their hoods, which acts as a not-so-subtle hint of what is mounted beneath. A main discussion point of many articles written about a potential X3 M over the past year was the mention of a possibility for the next-generation M TwinPower Turbo inline six making its debut in the SAV and now, BMW is touting a, “newly developed straight six-cylinder engine with M TwinPower Turbo technology and high-revving characteristics.”
Based on the N55 which was phased out in favor of the B48 starting back in 2016, the power plant of the current M3, M4 and M2 Competition is the S55. In production since 2014, a number of different versions of this engine have been released, including those for Competition Package-equipped M3’s and M4’s, a bespoke design for CS variants, and back in 2015, a highly-tuned water-injected variation exclusively destined for the engine bay of the M4 GTS. Most recently, a 405-horse version was debuted specifically for the M2 Competition, which replaced the previous N55-motivated M2.
The B58 came to market in 2016, initially under the hood of the F30 LCI 340i. Designed with modular construction and parts shared between the B38 three- and B48 four-cylinder engines, technological advancements cleared the way for a 20% increase in boost pressure, a closed deck block and high 11:1 compression. Technology is much the same as the N55, with direct-injection, a twin-scroll, pulse-tuned turbo, VANOS and Valvetronic all remaining present, but output has increased across the board, with entry level versions making comparable output to a Performance Power Kit-equipped N55, developing 322 hp between 5,500 and 6,500 rpm with 332 lb. ft. of torque available from just 1,380 to 5,000 revs. The most powerful version of the B58 is slated to arrive under the hood of the upcoming G29 Z4, but is also expected to be the power plant for the rumored G20 M340i 3 Series M Performance sedan, with output of over 380 HP and 369 lb. ft. of torque. The engine also sounds excellent, and revs enthusiastically to its 7,000 rpm redline, both of which have BMW fans itching to know more about a potential M derivative. Unfortunately, as of the time of this writing, no other information or specifics are known about the new engine, other than the future X3 M and X4 M will both be sporting it—at least we know it’s coming.
If you think it’s a bit odd for a new M engine to make its debut in an SAV or SAC, you’re invited to take a trip back to 2010 when BMW unveiled the now highly-respected S63 in the initial iterations of the X5 M and X6 M. That’s right, the S63 was first made available to the public via the X line, and not the since-replaced F10 M5.
Beyond the engines, the camouflaged exteriors of both upcoming M vehicles are bristling with tip-offs that include an array of gaping air intakes on the front, a quad exhaust at the rear and an interesting roofline spoiler on the back end of the greenhouse. Fender gills, aero and flared metal also appear to be present, and wheels look like an M-styled derivative of an underlying design language that has been used for years on X5 and others. Something else you won’t want to miss is the inclusion of an M xDrive system which is said to be a further development of the type on the F90 M5, that can be completely disabled to route motivation solely to the rear wheels.
Without knowing any real concrete details beyond what’s been made public, the X3 M and X4 M seem to offer a lot to be excited about, and BMW promises both will set benchmarks in their respectively vehicle segments which other manufactures will soon be measured against. —Alex Tock
[Photos courtesy BMW AG.]