The new 2025 BMW M5 is causing a sensation in the automotive world with its ultra-powerful plug-in hybrid powertrain. But this gain in performance is accompanied by a spectacular weight gain that raises questions about the evolution of this iconic sports sedan. Let’s analyze in detail the reasons and consequences of this excess weight.
Massive weight gain
The new M5 now weighs an impressive 2,444 kg. This figure represents an increase of more than 460 kg compared to the previous generation.. A colossal weight gain that is mainly explained by the adoption of a plug-in hybrid engine. This excess weight places the M5 in an unusual weight category for a sports sedan. It is now close to some large American SUVs in terms of mass. A paradox for a model that is supposed to embody agility and road performance.
The plug-in hybrid system in question
The origin of this weight gain lies in the new plug-in hybrid powertrain. BMW has chosen to combine a powerful V8 petrol engine with an electric motor and a large battery. While this configuration allows for an impressive combined power output of 717 hp, it also results in a significant increase in weight. The 18.6 kWh battery takes up a significant amount of space in the vehicle’s floor. Its weight is added to that of the already substantial 4.4-litre V8 biturbo combustion engine. The electric motor and power electronics further increase the overall weight. In total, this complex hybrid system weighs several hundred kilos.
A contested evolution
This massive weight gain of the M5 raises questions among enthusiasts. Some feel that BMW is moving away from the original spirit of the M5known for combining performance and agility. The high weight may indeed impact the dynamic behavior of the car, despite the efforts of engineers to hide it. Others defend this technological choice, arguing that it allows to combine high performance and energy efficiency. The ability to drive in 100% electric mode over short distances is highlighted as an asset. However, the electric autonomy limited to around 40 km seems low in view of the extra weight generated.
Mixed performances
Despite its record-breaking 717 hp, the new M5 fails to improve its acceleration performance. 0 to 100 km/h is announced in 3.4 seconds, 0.2 seconds more than the outgoing model.. A disappointing result that can be explained by the high weight of the vehicle. The power gain is largely absorbed by the additional mass to be put into motion. The M5 obviously remains an extremely fast car, but it loses efficiency compared to its lighter predecessor. An observation that questions the relevance of this technological development.
A phenomenon that affects the entire M range
The M5’s weight gain is part of a broader trend across the entire BMW M range. The sports division of the Bavarian manufacturer seems to have given up on the hunt for excess weight.. Unlike some competitors like Porsche, BMW M does not implement specific measures to limit the mass of its models. This approach questions the current philosophy of BMW M. The brand seems to favor raw power and equipment to the detriment of agility and efficiency. A choice that divides fans of the brand, between assumed modernity and nostalgia for a certain sporting purity.
More coherent alternatives?
Faced with this observation, some experts believe that BMW could have made other technological choices for the M5. A 100% electric engine, for example, would have made it possible to limit weight while still offering high performance.. The Porsche Taycan, lighter despite its electric motor, is cited as an example. Another possibility mentioned is that of mild hybridization, like the system adopted by Porsche on the 911. This solution would have made it possible to preserve the spirit of a thermal sports sedan while improving efficiency, without the extra weight of a large battery. But BMW does not yet have such a system in its range. The new BMW M5 2025 embodies the challenges faced by sports car manufacturers in the face of new environmental standards. Plug-in hybridization appears to be a transitional solution, but its impact on the weight of vehicles raises questions. BMW will undoubtedly have to find a better balance between performance, efficiency and mass in the coming years to preserve the sporty DNA of the M range.
