The 2021 Mercedes power unit features a number of completely new innovations as the team looks to continue its dominance of Formula 1.
Mercedes has won all seven drivers’ and constructors’ championships since the introduction of the V6 turbo power units back in 2014, with its engine a standout strength in that time. While performance levels have been converging since then, managing director of Mercedes AMG High Performance Powertrains (HPP) Hywel Thomas says work over the winter ahead of 2021 has focused on both reliability improvements and fresh development ideas.
“We are going into the eighth season of pretty stable regulations, so we have a good understanding of the current hybrid engines,” Thomas said. “Our new product is a characteristic Mercedes-AMG power unit, but we’ve worked hard to take the next development step. 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.”
While the works team tended to run consistently, reliability issues were more common for customers Racing Point (now Aston Martin) and Williams, and Thomas admits a lot of work has been done to improve the manufacture of the MGU-K specifically.
“We introduced a complete redesign in 2020, a very different MGU-K to what we had run previously. 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.”
But it’s not just the MGU-K that has been worked on for reliability purposes. Thomas explained that other aspects of the power unit needed attention, especially with a record-breaking season ahead.
“We’ve continued our quest for better thermal efficiency in the Internal Combustion Engine (ICE),” he said. “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 minimize 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 aluminum 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 (ERS), 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.”