Beginning in the inaugural season of the Porsche Supercup that Porsche Supercup cars used the naturally aspirated 180-degree flat-six engines but that time in 1993 Formula One were used the naturally aspirated various bank angle and various cylinders until end of 1994. Porsche Supercup cars had up to more compared to their Formula One counterparts, as early as in the 70s the cars had in excess of 1,000 hp. Porsche Supercup cars having on demand and F1 cars having around 700 hp to 840 hp in 3.5L NA (1989–94) era, around 700 hp to 1000 hp for final specs in 3.0L NA V10 (1995–2005) era and around 770 hp to 840 hp in 2.4L NA V8 (2006–2013) era and currently over 800 hp (2017 spec combustion engine alone) with an additional 160 hp from the electric motors from their 1.6L V6 turbo-hybrid-electro power unit. The turbo used mainly to improve the spectacle rather than lap-times with the so-called 'power-to-pass' or 'push-to-pass' system giving drivers an increased amount of power for a limited duration during the race. Another reason for retaining the turbocharger especially in Formula-1 is the muffling effect it has on the exhaust note, which helps keep the cars inside noise-limits, to meet FIA regulations and rules at the many city street races in European cities on the racing season schedule.