Why F1’s proposed 2027 engine changes could force teams to redesign half their cars. Proposed 2027 power unit changes could trigger extensive chassis modifications.

The debate surrounding Formula 1’s future engine regulations continues to intensify, with manufacturers and teams divided over a proposal that could significantly alter the balance of power in the sport. At the center of the discussion is the FIA’s idea of increasing the output of the internal combustion engine by at least 50 kW, roughly 70 horsepower, restoring a 60% thermal and 40% electrical power split instead of the current 50/50 ratio planned under the new regulations.

While the concept may appear straightforward on paper, the reality is far more complex. Simply increasing fuel flow into the cylinders does not automatically deliver the desired performance gains. Any significant rise in combustion-engine power requires extensive modifications throughout the power unit.

More fuel means new technical challenges

Increasing the output of the internal combustion engine would require engineers to revisit intake and exhaust parameters, recalibrate electronic control systems, and effectively redesign a substantial portion of the engine itself.

At present, only Mercedes and Red Bull Powertrains appear to be comfortably within the performance thresholds that would allow them to adapt more easily to a revised 2027 engine formula. Other manufacturers face a much more difficult situation.

Ferrari and Audi are believed to fall within the 2% performance deficit margin defined by the regulations, although Ferrari is reportedly closer to the target than Audi. Honda, meanwhile, is understood to be beyond the 4% threshold. As a result, these manufacturers must not only focus on improving their 2026 power units through the ADUO system—a mechanism often described as a form of financial balance-of-performance support—but also prepare for the possibility of developing a substantially revised, if not entirely new, engine for 2027.

Those chasing versus those protecting their advantage

For manufacturers currently trailing behind, the proposed changes effectively create two separate challenges for the price of one. They must first close the performance gap under the 2026 regulations and then potentially redesign their engines again to comply with the revised 2027 specifications.

However, the concerns extend beyond the power-unit suppliers. Teams themselves are increasingly worried about the broader implications of increased fuel consumption.

Modern Formula 1 cars carry significantly less fuel than they did in previous eras. Fuel tanks that once held around 110 kilograms of fuel have been reduced to capacities closer to 70-80 kilograms. If the internal combustion engine’s contribution is increased by approximately 70 horsepower, calculations suggest that fuel capacity may need to grow by roughly 10%, equivalent to an additional 7-8 kilograms.

That creates a second major problem. Current cars have been designed with packaging pushed to the absolute limit. Accommodating a larger fuel tank could require significant structural changes to the car itself.

Could chassis redesigns become necessary?

In normal circumstances, Formula 1 teams introduce updated chassis designs every season, so adapting to a larger fuel tank might not appear particularly problematic. However, the situation becomes more complicated when a team believes its existing chassis concept is already highly competitive.

If a team would otherwise prefer to carry over key elements of its current design philosophy, the requirement for a larger fuel cell could force a redesign that would not have been necessary under the original regulations.

This brings the discussion back to the manufacturers facing performance deficits. While they would need to invest significant resources in improving their engines, some teams could simultaneously find themselves having to develop new chassis solutions to accommodate revised fuel-storage requirements and changes in weight distribution.

It is easy to understand why certain manufacturers, particularly Ferrari, are reportedly resisting the proposal. The burden would fall disproportionately on those already trying to close the gap to their rivals.

Shorter races as a possible solution

One alternative being discussed is maintaining the current chassis architecture while reducing race distances by approximately 10%.

Using the Canadian Grand Prix as an example, a race that normally covers 70 laps and around 305 kilometres could be shortened by seven laps, bringing the total distance down to approximately 275 kilometres.

Supporters of the idea argue that the impact on the spectacle would be relatively limited. Fans would lose only around 15 to 20 minutes of on-track action while allowing teams to retain largely unchanged car designs and avoid extensive modifications to fuel systems and chassis structures.

Such proposals are also linked to Formula 1’s budget-cap era, which continues to place pressure on both technical development and staffing costs. According to some observers, financial restrictions are already affecting salaries across the paddock, with experienced personnel choosing to leave the sport as they face rising living costs and family commitments.

ADUO support currently applies only to Ferrari, Audi and Honda

The situation remains highly complex and requires a resolution sooner rather than later. If the ADUO concessions granted to Audi, Ferrari and Honda are intended to support power-unit upgrades expected to appear from the Belgian Grand Prix onward, manufacturers will still require additional time to prepare for any future regulatory changes.

Increasing internal combustion engine power inevitably brings higher fuel consumption and a series of knock-on effects. In the most extreme scenarios, teams could find themselves redesigning large portions of their cars, including engines, fuel tanks, weight distribution layouts and chassis structures.

For Formula 1, the challenge is to strike the right balance between improving the racing product and avoiding unnecessary costs. At the moment, that balance remains fragile—a familiar situation in a sport where technical, political and financial interests rarely align perfectly.