From an engineering point of view, the hybrid power units used in Formula One are truly mind-blowing in terms of their thermal efficiency - in other words, their ability to convert fuel energy into useful work. When the internal combustion engine was developed by Nicolaus Otto in 1876, it had a thermal efficiency of about 17 percent. That means that only around 17 percent of the energy in the fuel was converted into useful work.
In 2013, one year before the introduction of hybrid power units in Formula One, the thermal efficiency of an average road car reached roughly 30 per cent, meaning that only about one third of the petrol in the car was used to propel it. In the summer of 2017, the staff at Mercedes-AMG High Performance Powertrains in Brixworth, UK ran a Mercedes-Benz F1 power unit on their dyno - and it showed an astonishing number. The F1 M08 EQ Power+ power unit reached a thermal efficiency of over 50 percent, making it the one of the most efficient internal combustion engines ever.
F1 hybrid power units are not just very efficient; they also have made considerable contributions to battery technology. The first energy recovery system was used for development testing in 2007, its energy store weighed 107 kilograms and achieved 39 percent efficiency. Since then, the weight has been reduced by over 80 percent; today, the lithium-ion battery energy store has a 20 kg minimum regulation weight. The efficiency has increased by 57 percentage points, reaching 96 percent today. At the same time the energy density has doubled while the power density has increased 12-fold.
The research that has gone into making an F1 car as performant as possible does not just give the team an advantage on the track, it also helps to make road cars more efficient; the same learnings that deliver improved power for racing, can also be applied to improving fuel consumption in the road-going environment.