The 2025 BMW M5 Needs to Decide If It’s for Business or Pleasure


Fabian Kirchbauer
It’s a rare day when BMW reveals a new M5. It’s only happened seven times in human history, after all — and when it comes, it’s always met with strong reactions from the legions of fans. Yet when the Bavarian Motor Works revealed the latest generation, known internally as the G90, in April of 2024, the response was skewed unusually strongly towards the negative. New M5s always spark some controversy — It’s ugly! There’s no manual! It’s as long as a 7 Series used to be! — but the brouhaha over the latest one felt different. It would be easy to credit it to the darkened state of online discourse in 2024 … but in reality, it was a complaint about weight. At 5,390 lbs, the seventh-gen M5 weighs around 1,100 pounds more than its predecessor, even though its dimensions have barely grown.
Why? Three words, or two if you bundle them with your hyphens: plug-in hybrid. For the first time, the M5 was merging gasoline and electric propulsion.
At the heart of the G90 sedan and G99 station wagon (better known as the M5 Touring) lies the same powertrain pioneered by the little-loved XM crossover: a 4.4-liter twin-turbo V-8, and an electric motor connected to the eight-speed automatic and fed by a 14.8-kilowatt-hour lithium-ion battery pack. The maximum combined output of this gas-electric combination comes to 717 horsepower and 738 lb-ft of torque, a full 90 horses and 186 lb-ft more than the most potent version of its predecessor, the M5 CS. But the added mass means each of the new M5’s ponies must push around 7.52 pounds; the hard-edged M5 CS boasted a superior 6.53 lbs/hp. Even the more mainstream M5 Competition of yore — a closer analog to this new model — only had to wrangle 6.88 lbs per horse.
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Image Credit: Fabian Kirchbauer As anyone who’s ever picked up a new battery for their car or bought a home power station know, batteries are dense, which makes them weighty. Electric motors are dense hunks of metal, thus are heavy; power cables thick enough to carry the heavy electron flow needed to generate hundreds of horsepower are also not light. And all that extra equipment requires additional bracing and structure to keep it from sloshing around … which, in turn, adds more weight. (In an interview with Top Gear, the BMW M division’s head, Frank Van Meel, admitted that the hybrid system adds about 400 kilograms, or 880 pounds, of the 1,100-lb gain.)
That’s not to say PHEVs, as they’re known, are a bad idea. Plug-in hybrids are an excellent choice for vehicles where efficiency or comfort is the primary goal. Unlike conventional gas-powered cars, they offer zero-emission driving; unlike EVs, it offer hassle-free road tripping. Moderate-sized batteries mean even a household outlet can suffice to recharge the car overnight, delivering enough range for the average commute. For the driver who sees their vehicle as simple transportation, whose priorities lie with reducing greenhouse emissions, or simply who doesn’t care about what powers their car all that much, a plug-in hybrid can make a ton of sense.
For performance cars, however, they’re less of an ideal proposition — because, as the M5 demonstrates, their added power is often largely offset by the bonus mass of the PHEV system. A guiding principle for many a sports car engineer over the decades has been Colin Chapman’s maxim of “Simplify and add lightness.” PHEVs complicate and add weight.
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Image Credit: BMW Now, it’s not impossible to find a balance between hybrid heft and high performance. Chevrolet’s Corvette E-Ray and Porsche’s 911 Carrera GTS-T both use more traditional mild hybrid systems to boost power significantly over their non-electrified counterparts; Ferrari and Lamborghini even manage to do so using PHEVs, in the former’s 296 GTB / GTS and SF90 Stradale and the latter’s Revuelto and Temerario. But the Italian supercar companies do so by using as little battery as possible. The Revuelto can only travel six to eight miles on electrons alone — enough to get out of earshot from home before firing up the V12 on an early morning weekend drive, but not much beyond that.
The assumption, of course, is that nobody is buying a two-seat sports car with a primary focus on commuting, so there’s no reason to give it any more battery than is needed to deliver the advertised maximum power. The M5, however, is a sport sedan — a car meant not just to deliver thrills on back roads, but also to shuffle to work in urban cores — many of which in Europe now feature low-emissions zone laws that penalize vehicles that pollute beyond a certain level. It’s forced to serve two masters in a way a Corvette or 911 or Italian exotic simply doesn’t have to.
The M5’s situation is shared by some of its fellow German luxury carmakers as they also press farther into the world of electrified motoring. Mercedes-AMG caught flak for the new C 63 S E-Performance when it debuted back in 2022, although that ire was as much about the decision to replace the V-8 that defined it with a turbocharged inline-four combined with electric propulsion. And all but two of the six powerplant variations of Porsche’s latest Panamera boast both a plug and a gas tank.
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Image Credit: Fabian Kirchbauer Even by the standards of its peers, however, the M5 is lardy. The Panamera Turbo S E-Hybrid, for example, gained roughly 700 lbs over the previous gas-only Panamera Turbo S, while the C 63 tacked on more than 750 lbs versus its immediate ancestor. And both of those at least offer 0-60-mph times quicker than the cars they replaced; the G90 M5, meanwhile, will take 3.4 seconds to go from naught to a-mile-a-minute, according to BMW — a fifth of a second more than it claimed the previous F90-gen needed.
Of course, like Mercedes-Benz and Porsche and every other global carmaker, BMW is laboring under the looming threat of increasingly strict emissions standards coming down from regulatory bodies across the planet, aimed at leaving only EVs — and, perhaps, some PHEVs — available in new car showrooms by sometime in the next decade. As part of this, governments from California to Great Britain to the European Union are gradually reducing the percentage of ICE machines automakers can sell each year. But the M5 is ultimately a drop in the bucket compared to all the gas-powered SUVs the brand sells — or even within the broader 5 Series lineup, which already features mild hybrid, plug-in hybrid, and fully electric options. In fact, BMW has no shortage of electric cars, and plans to build far more; the M division is hard at work developing its own take on such a machine. How much of a difference can a few thousand PHEV M5s really make?
And from the consumer side, the efficiency benefits of the added battery capacity seem middling. The M5’s battery pack enables it to travel 25 miles on electricity alone, the carmaker says — significantly more than the AMG, but less than the Porsche, which boasts around 30-40 miles of electric driving thanks to its larger battery. In gas-free mode, the M5 is limited to the electric motor’s 194 horsepower — acceptable for a Honda Civic, perhaps, but not for a 5,400-lb luxury car. And yes, mashing the pedal to the firewall will summon the whole powertrain’s fury in a pinch … but that defeats the purpose of trying to go green.
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Image Credit: Fabian Kirchbauer There are carmakers who are managing this transition better. The latest Bentley Flying Spur Speed trades in its twin-turbo W-12 for the same power plant as the Panamera Turbo S E-Hybrid, giving it identical figures to the maximum PHEV Porsche. The new powertrain improves the Bentley in basically every way: it’s more powerful, more efficient, more aggressive at full attack and more refined when wafting about. And because Bentleys are, by nature, massive, the plug-in hybrid setup is less of a burden, percentage-wise: while the M5 is 25% heavier than its predecessor, the Flying Spur Speed hybrid weighs just 5% more than the 12-cylinder version that came before.
Impressive as the old Speed was and the new one is, however, they have never been enthusiast cars — ones that develop their own legends, inspire fan clubs, become larger than life based on their acceleration and braking and handling, and appearance. The M5, by contrast, is. Over the generations, this BMW has become a performance car icon, beloved for its seamless, often peerless ability to not just accomplish both mundane daily tasks and full-throated driving excitement, but to bring a little delight into the former and a little practicality to the latter. It’s hard to imagine those fans, the ones who made the M5 what it is today, are the ones who wanted the feature of 25 miles of all-electric driving — and certainly not at the expense of an extra half-ton of weight.
If BMW wants the M5 to cater more broadly to everyone, it runs the risk of alienating the core demographic of enthusiasts that made it a legend in the first place. The automotive history books are thick with defunct models that tried to be too many things to too many people and wound up being the wrong thing for most.
The M5 has always been an enthusiast car — or at least, enthusiasts have always thought of it as one. Whether the Bavarian Motor Works of this day and age see it that way, it seems, is another question. Because with the new M5, it feels like BMW is attempting to have its cake and eat it too — and too much cake inevitably means bad news on the scale.