Turbocharged: 2015 BMW M3 Sedan/M4 Coupe

Amidst a slew of exciting new vehicles revealed at this year’s 2014 North American International Auto Show (NAIAS) in Detroit on January 13, the brand-new 2015 BMW M3 sedan/M4 coupe stood out. If you’re somehow unfamiliar with the massively impressive legacy of BMW’s M line, know that these machines are all about speed, acting as the most aggressive of all of BMW’s offerings. Prior to 2015, the high-performance M3 was a single line with a sedan and coupe version, just like the regular, non-M 3 Series. Now, BMW has split the M3 into two distinct lines in order to match the reconfiguring efforts they’ve made along their other vehicle lines. The M3 coupe version will now be known as the M4, while the sedan will retain the M3 moniker. This follows BMW’s new naming scheme, which applies an even-numbered naming convention to vehicles with two doors, and an odd-numbered naming convention to those with four doors.

BMW’s M line has long been regarded by many as racing at the head of the pack of all other sport sedans and coupes, setting the benchmark by which newcomers and imitators are measured. In recent years however, various automakers are successfully playing catch up to the M series, notably Lexus and Cadillac. With this in mind, BMW has looked to shake up the 2015 M3/M4 in a far more substantial manner than simply rebadging the line. The German automaker has pulled from their race car engineering know-how dating back all the way to 1960 in order to allow the 2015 M line to outpace their competitors, with considerable upgrades to engine output, vehicle size and weight, and fuel efficiency, alongside the expected exterior design tweaks and refinements. Let’s take a look at what they’ve accomplished.

5 Power

The name of the game with the refresh of the M3 sedan and the rebadging of the M3 coupe as the M4 is power. The new twin-turbocharged 3.0-liter inline-six, while losing a liter of displacement, still manages to out-muscle the naturally aspirated 4.0-liter V8 seen in previous incarnations of the BMW M3 sedan/coupe. This is in large part thanks to BMW’s M TwinPower Turbo forced-induction system. There’s a lot of technical know-how and engineering that went into this system, but the most salient takeaway is that the engine’s output is 425 hp (between 5,500 and 7,300 rpm) and 406 kb-ft of torque thanks to two low-inertia turbochargers providing 20.15 psi of boost pressure. If those numbers perhaps sound “wow” worthy, it’s because they are. The outgoing BMW models, powered by the aforementioned V8, produced just 414 hp and 295 kb-ft of torque.

The new powerplant on the 2015 BMW M3 sedan/M4 coupe bears other advantages over the outgoing design, as well. The six-speed manual iterations offer 0-60mph in 4.1 seconds, while the dual-clutch transmission offers up 0-60 mph times of a startlingly low 3.9 seconds.

4 Size and Weight

It isn’t just about power, though. The new models have been on a diet, dropping several hundred pounds over their predecessors. This doesn’t mean leg room, head room, or any other kind of room has been sacrificed to compensate. Actually, quite the opposite. The new M3 is 2.8 inches wider, 3.6 inches longer, and 0.9 inches higher, while the new M4 is 2.6 inches wider and 2.2 inches longer. It’s also 1.7 inches lower than the outgoing M3 coupe.

How is this all achieved? The use of some high-cost, fancy materials, including carbon fiber and aluminum. The 2015 M3 will weigh 3,351 pounds, while the M4 coupe will weigh in at 3,300 pounds. The drastic difference in weight is due to a number of specific adjustments. The new carbon roof plays a large role, but there are several other differentiaters which in aggregate add up to some noticeable weight savings. The new 3.0-liter inline-six manages to be 22 pounds slimmer than the old 4.0-liter V8. The vehicle’s crankshaft has been slimmed down by 6.6 lbs, while the crankshaft case is also approximately 6 lbs lighter. The rear seats are also 11 lbs lighter in comparison to the non-M variants of BMW’s 3 and 4 series. Finally, if you feel like stepping up to the carbon ceramic brakes as an additional cost option — and why not, with a machine of this caliber — you’ll save an additional 13 to 15.5 lbs. The little tweaks all add up to a speed demon that can whip up and down roads with a particularly impressive ferocity.

3 Fuel Efficiency

What’s the other natural result of a smaller, smarter engine (albeit turbocharged for extra power) and a substantial cut in weight using new materials and redesigned components? Fuel efficiency. Recent BMW vehicles have not at all been among the most offensive of gas guzzlers despite their legendary performance, but all that speed and acceleration did take a toll on miles per gallon. All these 2015 improvements, however, have led to substantially better fuel performance that really starts to put BMW on more of an even field fuel consumption-wise with less powerful sedans and coupes, as BMW has quoted a roughly 25 percent improvement in fuel efficiency. That’s an impressive jump for a set of vehicles with as much of a mean streak as the 2015 M3 and M4.

2 Exterior Design

BMW hasn’t left the exterior aesthetics of the 2015 M3 and M4 alone, despite their focus on power and weight. A bolder front fascia includes tweaked quad headlamps that now may come as optional adaptive LED units. The twin-bar kidney grille is accented with black, and the power-dome hood has lines that aggressively sweep back to the new carbon roof. Air breather vents and M gills on the front fenders are noticeable when moving from the front of the vehicle to the side. The M’s wheel arches are now filled with 275/40 rubber at the rear and 225/40 rubber at the front, and accompany 18-inch forged alloy wheels.

Perhaps the most distinct new exterior tweak to the M line for 2015 occurs at the rear. The rear fascia is edgier, and each model features a unique taillamp setup. Additionally, the M3 features a spoilerette while the M4’s decklid offers an integrated spoiler lip.

1 Price and Options

All these improvements in weight, engine design and aesthetics do come at a cost when compared to previous iterations of the BMW M3 line, of course. The 2015 BMW M3 sedan will go on sale for $62,000 while the 2015 BMW M4 coupe will hit show floors at $64,200. An additional $925 destination fee will be tacked on for both vehicles, and each will be available as of the summer of 2015.

A slew of purported options have been rumored for the new M3 and M4, and are included below.


CSAT – Cloth/Leather combination Carbonstructure Anthracite/BlackX3A9 – Silverstone Full Merino LthrLKA9 – Silverstone Extended Merino LthrX3DA – Sakhir Orange/Black Full Merino LthrLKDA – Sakhir Orange/Black Extended Merino LthrX3JR – Sonoma Beige Full Merino LthrLKJR – Sonoma Beige Extended Merino LthrX3SW – Black Full Merino LthrLKSW – Black Extended Merino Lthr

ZDB – Driver Assistance Plus5AG – Active Blind Spot Detection5AS – Lane Departure Warning w/Collision Mitigation5DL – Side and Top View Cameras8TH – Speed Limit Info

ZEC – Executive Package

248 – Heated Steering Wheel322 – Comfort Access keyless entry3AG – Rear-view camera494 – Heated Front Seats502 – Retractable headlight washers508 – Park Distance Control610 – Head-up Display655 – Satellite radio with 1 year subscriptionLK – Extended Merino Leatheror X3 – Full Merino Leather

ZLP – Lighting Package

552 – Full LED Lights5AC – Automatic high beams

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