Since its launch, the Mazda RX8 has been the subject of close scrutiny by enthusiasts. The high level of attention is not only due to the car's admirable driving dynamics but, in part to the early reports of below-than-expected performance. To be more specific: wheel horsepower measured on several chassis dynamometer runs resulted in values well below the expected 17%~20% drivetrain parasitic losses. And quarter mile runs of anywhere between 0.5 and 1.5 seconds off of those produced by magazines on allegedly pre-production vehicles.
In connection with the RX8's horsepower rating: the original marketing material from Mazda North America (MNAO) advertised the 6 speed manual transmission RX8 at 247hp @ 8,500rpm. Assuming parasitic drivetrain loses between 17%-20% -common for modern rear wheel drive vehicles, a stock RX8 should measure between 205~197 horsepower at the rear wheels (rwhp) -depending on elevation, barometric pressure, temperature and correction factors applied. Instead, a stock RX8 chassis dyno run shows results ranging anywhere from mid-high ~160 to ~185rwhp. Such readings would represent parasitic drivetrain loses in excess of 25%. To say that, it is unacceptable to experience such a high level of loss through the drivetrain of a "sports car" with a carbon fiber drive shaft -amongst other things- is an understatement.
To further consolidate doubts about the actual power output of the new Renesis, several owners were unable to reproduce mid-low 14 second quarter mile passes -as seen published by well known U.S. car magazines. Low trap speeds were another hint towards the apparent lack of power output.
Shortly after, several debates on online enthusiast forums and discussion boards turned into heated arguments as to what was causing such poor "straight line performance." Many former Miata owners remembered a previous "snafu" in Mazda's history, when the manufacturer admittedly overstated the horsepower figures of their redesigned Mazda Miata.
