Lewis Hamilton's chances of securing a record eighth title will be boosted by Ferrari's decision to redesign its 2027 power unit so heavily that it will effectively be a new design.

Hamilton said in Mexico City that Ferrari would be fighting for this year's championship if its engine matched the power of its rivals, as he identified the team's major weakness this season.

Ferrari's latest aero upgrade explains why the engine is now under the spotlight. The team introduced its final major aerodynamic upgrade package of the season at the United States Grand Prix in Austin, and it delivered encouraging results. The result in Texas built on a run of earlier upgrades. Those upgrades have also helped compensate for some of the limitations imposed by the Ferrari power unit, whose performance has remained a relative weakness.

Hamilton puts the title gap down to the engine

At Thursday's media day in Mexico City, Hamilton said plainly what Ferrari needs to work on most. "I think the engine is probably number one [priority]. We've got reliability, which is good. But if we were matching the power of the others, we would be fighting for the championship this year, which we know," he said. He added: "So rectifying that and closing the gap is important."

The seven-time world champion also made clear that his focus has already moved to next season. "I think these next five races are like test races," he said. "For me, I'm really focused right now on next year's car, looking at the good things from this year and making sure we don't lose them, but instead add to the chassis. And then, of course, in the background, I'm pushing as hard as I can to make sure we come with a power unit that can compete with Mercedes and Red Bull."

Ferrari target a fundamentally new power unit

Ferrari's engine deficit was not caused by packaging compromises made to help the aerodynamics so it cannot be fixed through bodywork. Instead it believed it related to a smaller-diameter turbine, a conceptual choice that has influenced engine performance independently of how the unit is installed in the chassis.

Ferrari's next engine must come without the limitations of the current design. A full season of performance data now shows engineers which areas need a fundamental rethink, and the changes are expected to be extensive enough that Ferrari's 2027 power unit will effectively represent an entirely new design.

Ferrari have already used their 2026 engine upgrades

Ferrari's engine has been a weak spot all year. In July the Ferrari power unit was judged to be over 4% off, so it's been granted two mid-season upgrades and two for 2027 as part of the FIA review.

The second upgrade came at Monza in September, but team principal Fred Vasseur admitted afterwards that the car was still missing "pure power" compared with Mercedes-powered rivals.

There is still plenty at stake in the final rounds. Ferrari are second in the teams' standings, but with Red Bull closing quickly due primarily to Max Verstappen's two race wins in quick succession.