Mercedes fix MGU-K issue with ‘completely new innovations’ on 2021 F1 engine

Mercedes' 2021 Formula 1 power unit features some “completely new innovations” in the quest for greater performance and reliability.

The reigning world champion squad unveiled its 2021 challenger - the W12 - and revised livery on Tuesday morning ahead of its bid to win an eighth consecutive world championship double this year.

Despite the significant carry-over of mechanical parts between last season and this one, Mercedes’ W12 features “considerable aerodynamic changes alongside improvements to areas as such as the suspension, cooling system and Power Unit”.

Mercedes engine chief Hywel Thomas revealed the changes the team has made in order to extract even more performance and reliability from its latest car, having recently admitted the team was battling to resolve “some issues” with its new power unit.

“Our new product is a characteristic Mercedes-AMG Power Unit, but we’ve worked hard to take the next development step,” Thomas explained.

“Stable regulations mean that it’s getting increasingly challenging to unlock additional performance, so you need a focused approach.

“We identified three main areas to work on: first, we’ve continued the development of the technology in the Power Unit. That’s a continuous process, and we feel like we’ve been able to take a step forward on that front again this year.

“The second area is reliability. We discovered some design issues last year, so we’ve been looking at those and introduced some changes to address them. And we’ve also got some completely new innovations that will be in the racing PU for the first time.

“That was particularly challenging because last season finished late, so the winter period has been shorter than normal and has given us less time to prepare, which put extra strain on the business.”

Thomas also revealed Mercedes has successfully fixed the reliability issues it encountered with its MGU-K last year.

“We introduced a complete redesign in 2020, a very different MGU-K to what we had run previously,” he added.

“It helped us make a solid step forwards in performance, but it was a design that turned out to be difficult to manufacture and assemble consistently.

“We had lots of examples where the MGU-K ran a full cycle and did exactly what we wanted it to do, but we also had some cases of midlife failures. For 2021, we’ve gone back, looked at that design and built an understanding of where the failures have come from.

“We have changed it for this year, to allow for a more consistent manufacturing route which should help to improve the reliability of the MGU-K.”

Mercedes has focused its engine development on achieving increased thermal efficiency in the ICE, as well as making changes to the turbocharger, introducing a new allow for the engine block, and adjustments to the ERS in a bid to further increase reliability ahead of a record-breaking 23-round season.

“We’ve continued our quest for better thermal efficiency in the Internal Combustion Engine,” Thomas explained.

“Most of the developments can be found in the core of the Power Unit, with a desire for maximum output from the combustion process.

“Hand in hand with that, we’ve introduced changes to the turbocharger to minimise the impact on the heat rejection. Those are probably the most striking when it comes to crank power and the performance of the Power Unit.

“We’ve also completed some work on improving the reliability of the PU. In 2020, we used an aluminium structure which wasn’t as reliable as intended, so we’ve introduced a new alloy for the engine block. We’ve also made some adjustments to the Energy Recovery System, to make it more resilient.

“We’ve got a big challenge in 2021 with 23 races on the calendar, we will need to ensure that the reliability of the Power Unit is spot on. We’ve worked hard on that area and hopefully it’s paid off.”