Reader Response Draft 3 (submission)

The article “Mercedes F1 W05 Hybrid” introduces the PU106A Hybrid power unit. The main function of the PU106A Hybrid was to power the Mercedes W05, developed by the Mercedes AMG Petronas Formula One Team in the 2014 Formula One season. The PU106A Hybrid can be separated into two parts: the V6 internal combustion engine (ICE), equipped with a turbocharger, and the hybrid system. According to the Cummins website (n.d.), the turbocharger allows more compressed air into the ICE to produce more power during the combustion phase while the Energy Recovery System (ERS) is the hybrid system of the car. Blackstock (2022) said that the ERS consists of 3 components: the Motor Generator Unit-Kinetic (MGU-K), Motor Generator Unit-Heat (MGU-H), and the Energy Store (ES). The ERS harvests energy from various parts of the car such as the brakes and turbo compressor, which is stored in the ES in the form of electricity. The electricity is then discharged to the respective motor generator units to give additional power directly to the engine or turbocharger. Fagnan (2016) conducted an interview with Rémi Taffin, the Director of Operations at Renault Sport F1. Taffin explained that the MGU-H is located between the turbine and compressor of the turbocharger to eliminate turbo lag. The same article also explains that the MGU-K is connected to the crankshaft, which helps it to rotate when throttle is applied by the driver. The 2013 season was the last to see the gas-guzzling, ear-piercing V8 engines. In 2014, F1 directives introduced the new V6 turbo hybrid engine—a new era of racing. With the F1 regulations having their focus switch towards efficiency and sustainability, the newly designed PU106A Hybrid is a clear improvement compared to the FO 108F, a naturally aspirated V8 engine also designed by the Mercedes F1 team in 2013.

One of the advantages the PU106A Hybrid has is its superior hybrid system compared to the FO 108F’s Kinetic Energy Recovery System (KERS). The KERS was the predecessor of the ERS, as Blackstock (2022) suggested. It mainly consists of a Motor Generator Unit (MGU), connected to the crankshaft, and a battery. The MGU is able to harvest the heat energy from the brakes produced under braking and convert it into electricity, which is stored in the battery, as explained from a blog post by Canbolat (2020). According to Mie (2013), the MGU-K works almost exactly the same way, but more efficiently as it works in tandem with the MGU-H. Overall, the KERS is only able to deploy an extra 80 horsepower for 6.7 seconds per lap, while the ERS deploys 161 horsepower for 33.3 seconds per lap. From this, we can tell that the 2014 hybrid system, ERS, is far better than KERS.

Another advantage is that the V6 engine of the PU106A Hybrid is more fuel efficient than the FO 108F V8 engine. Holt (2013) mentions that the PU106A Hybrid has a regulated flow rate of 100kg of fuel per hour, 50kg less than the FO 108F. It is able to achieve this by having two fewer pistons and a downsized engine displacement from 2.4 to 1.6 litres. Furthermore, with the help of a fully-fledged hybrid system, the ICE of the PU106A Hybrid does not have to produce as much power during acceleration. The MGU-K helps to drive the crankshaft of the engine, while the MGU-H spins the turbo continuously when the driver is off the throttle to provide instantaneous power. The FO 108F, however, has to rely mostly on its ICE as the KERS is commonly used as a “boost” to attack or defend from other drivers. This suggests that with a smaller engine and a better hybrid system, the engine is able to run less fuel across the whole race.

One problem with the PU106A Hybrid is that the FO 108F was deemed faster on track despite the added turbocharger and hybrid system. According to statistics collated by Mie (2015), the PU106A Hybrid is 2 to 3 seconds slower on average in qualifying pace and race pace. Since the PU106A Hybrid is relatively new to the sport, Walthert (2014) explained that “it will take time for engineers to unlock the cars’ full potential”. Furthermore, the FO 108F was the last iteration of the V8 engines produced from 2006 to 2013 and went through several years of research and development. This suggests that it will take several years for the V6 turbo hybrid engine to catch up with the performance of the V8 engine in terms of lap times.

In conclusion, Formula 1 had to move on from the ageing V8 engine technology of the FO 108F. As the new PU106A Hybrid made its way into the racing scene in 2014, the V6 turbo hybrid was able to push the boundaries of hybrid technology and engineering marvels more than the previous generation of engines could.

References

Blackstock, E. (2 August, 2022). Motorsport Explained: Formula 1's MGU-H and MGU-K. JALOPNIK: https://jalopnik.com/motorsport-explained-formula-1s-mgu-h-and-mgu-k-1849355365

Canbolat, A. (19 August, 2020). Basics of Kinetic Energy Recovery System (KERS). Medium: https://medium.com/@alpoller/basics-of-kinetic-energy-recovery-system-kers-29e621b16319

David, D. (13 June, 2015). Mercedes F1 W05 Hybrid. Sports Car Digest: https://sportscardigest.com/mercedes-f1-w05-hybrid/

Fagnan, R. (24 June, 2016). Technique - The MGU-K and MGU-H explained. motorsport.com: https://us.motorsport.com/f1/news/technique-the-mgu-k-and-mgu-h-explained-791187/2986353/

Holt, S. (4 December, 2013). F1 rips up the rulebook: The 2014 changes explained. CNN: https://edition.cnn.com/2013/12/04/sport/motorsport/f1-2014-rules-changes/

How a Turbocharger Works. (n.d.). Cummins: https://www.cummins.com/components/turbochargers/how-a-turbocharger-works

Mie. (14 October, 2013). How F1’s Energy Recovery System (ERS) will work in 2014. The Parc Ferme Podcast: https://theparcferme.com/how-f1s-energy-recovery-system-ers-will-work-in-2014/

Mie. (23 November, 2015). Then and Now – Lap Time Comparison. The Parc Ferme Podcast: https://theparcferme.com/then-and-now-lap-time-comparison/

Walthert, M. (25 March, 2014). Are 2014 Formula 1 Cars Slower? Analysing Lap Times at Australian Grand Prix. Bleacher Report: https://bleacherreport.com/articles/2003467-are-2014-formula-1-cars-slower-analysing-lap-times-at-australian-grand-prix