TECH ANALYSIS: Mercedes Targets Key Weakness in New W16 for Russell and Antonelli
Mercedes’ new W16, while visibly related to last year’s car, incorporates changes to address its two main shortcomings, as explained by Technical Director James Allison. “Being the fourth year of these regulations on the chassis side, the cars are in a more mature phase. Big gains in lap time are harder to come by, but we’ve been concentrating on making improvements in the areas that held us back last year,” Allison stated. “Our primary focus has been on dialling out the W15’s slight reluctance to turn in slow corners, along with the imbalance in tyre temperatures that made the car inconsistent from session to session.”
Similar to Ferrari – but unlike McLaren – Mercedes has targeted a specific weakness from the 2024 model. While Ferrari’s and Mercedes’ issues were different, both highlighted the challenge of achieving good downforce and a driveable balance through both low-speed and high-speed corners within the current regulations. Ferrari struggled with high-speed downforce, while the Mercedes excelled in high-speed corners but faltered in low-speed sections where Ferrari shone.
Mercedes unveiled the W16 shortly before the 2025 pre-season testing.
Mercedes aims to achieve a more balanced performance across different speeds while retaining the basic chassis geometry and suspension layout (push-rod front and rear) of the W15. The gearbox is carried over from 2024, reflecting the fact that cockpit positioning and wheelbase remain unchanged. The primary changes are in the aerodynamic surfaces.
The W16’s front wing, based on initial renderings, has a slightly revised flap geometry compared to its predecessor, with the flaps retaining greater depth towards the outboard section. Furthermore, the nose, which appears slightly narrower, now merges with the bottom mainplane of the wing without a slot gap to the floor. The underside of the nose is also scalloped out to create a negative pressure area, which improves airflow and enhances the downforce acting directly on the front axle.
Without the slot gap, this effect will be enhanced. It seems Mercedes has tried to shift the aerodynamic emphasis towards the front at low speeds, where understeer is a key limiting factor, even at the expense of some rear downforce.
But that balance changes at different speeds. As the effect of downforce compresses the car on its suspension, the front wing may become too powerful, necessitating a more rearward aero balance – meaning the downforce on the rear axle needs to increase more than at the front. Previously the slot gap helped with this. With that no longer there, Mercedes appears to be trying to enhance the flow to the rear corners of the car (between the rear tyre and diffuser) with an undercut section running the length of the sidepod (like the 2011 Toro Rosso STR6), forming a channel with a wide funnel beneath the new radiator inlets.
A notable hump on the sidepod’s underside (likely to accommodate the bottom of the radiator) slightly narrows the height of the floor edge channel and may create a venturi effect, accelerating air along the car. The airflow down this floor edge and that of the underfloor meet around the diffuser, closely related. The higher the energy of the airflow along the floor edges, the greater its pull on the underfloor flow. The goal is for downforce created by this method to increase with speed at rate than that of the front wing.
The re-design of the Mercedes’ radiator inlets plays a key role in creating the full-length undercut. A Red Bull-like vertical inlet sits tight against the bodywork sides, along with a more intricately shaped horizontal inlet. The entire sidepod front is now more rounded, which should improve flow into the undercut and along the channels. The aerodynamics of the 2024 Mercedes were optimized for very low ride heights, giving it superior performance on smooth, fast tracks. However, performance decreased when the ride height needed to be raised for bumpier tracks.
So far, McLaren seeks to maintain its existing balance but with more added downforce, Ferrari looks to eradicate its high-speed deficit through a fundamental chassis change, and Mercedes is addressing its slow corner weakness with a new aero balance.
