September 20, 2024
Mazda RX8 Horsepower Controversy

Because its launch, the Mazda RX8 has been the topic of shut scrutiny by lovers. The higher level of notice is not only owing to the car’s admirable driving dynamics but, in element to the early stories of below-than-expected overall performance. To be far more particular: wheel horsepower measured on several chassis dynamometer operates resulted in values properly underneath the envisioned 17%~20% drivetrain parasitic losses. And quarter mile runs of any where involving .5 and 1.5 seconds off of those created by publications on allegedly pre-manufacturing automobiles.

In link with the RX8’s horsepower rating: the first advertising and marketing material from Mazda North The usa (MNAO) advertised the 6 velocity handbook transmission RX8 at 247hp @ 8,500rpm. Assuming parasitic drivetrain loses between 17%-20% -typical for modern-day rear wheel push cars, a stock RX8 should measure involving 205~197 horsepower at the rear wheels (rwhp) -based on elevation, barometric strain, temperature and correction components utilized. Alternatively, a inventory RX8 chassis dyno run demonstrates benefits ranging everywhere from mid-high ~160 to ~185rwhp. This kind of readings would depict parasitic drivetrain loses in surplus of 25%. To say that, it is unacceptable to encounter such a high degree of decline as a result of the drivetrain of a “athletics vehicle” with a carbon fiber drive shaft -among other matters- is an understatement.

To more consolidate doubts about the true electric power output of the new Renesis, a number of owners were being not able to reproduce mid-minimal 14 2nd quarter mile passes -as seen revealed by nicely acknowledged U.S. automobile magazines. Low lure speeds had been one more trace in the direction of the clear absence of power output.

Shortly after, a number of debates on on the internet enthusiast community forums and discussion boards turned into heated arguments as to what was creating these types of lousy “straight line functionality.” Many previous Miata homeowners remembered a previous “snafu” in Mazda’s historical past, when the company admittedly overstated the horsepower figures of their redesigned Mazda Miata.

After a few months, MNAO arrived forward and explained that they had misrepresented the Renesis’ ability output. The revised figure was now 238hp @ 8,500rpm however, in accordance to MNAO, this revision did not improve the beforehand attained observe efficiency effects.

Speculations about the motives guiding the sudden lack of electric power output ended up many. Even so, there are at present two educational facilities of believed:

  • The first a person supports the thought that the RX-8’s motor administration unit (Eu), in conjunction with the numerous “nanny” devices -these types of as Stomach muscles & TCS- do not allow to receive precise readings from a chassis dynamometer. To simplify, when the auto is run on a chassis dyno, only the driven wheels are turning. The RX-8’s Eu would detect an abnormal driving situation and retard timing and use other protection measures to protect possibly the “driver” or the “motor” -or each- from destruction (read through: skidding predicament, or a motor vehicle likely out of the road.)
  • The second a single believes that MNAO was forced to re-engineer the software program that operates the engine administration even before the initial batch of RX-8’s arrived at U.S. shores, due to approaching Federal emissions laws. I have go through of a single in particular, which necessitates catalytic converter lifespan of ~100,000 miles. The enemy variety a single of catalytic converters on any vehicle is warmth (and warmth is the quantity one particular attribute of rotary engine’s exhaust gases.)

MNAO offered two selections to these who had pre-requested an RX-8, or experienced purchased no late than September 2003:

  • They would invest in back the motor vehicle, no concerns asked.
  • They would supply Free of charge Scheduled Servicing for the lifestyle of the guarantee, additionally a 500 dollar “present card” to these who opted to maintain the motor vehicle.

I was among individuals who opted to keep their RX-8. Soon after all, the driving expertise experienced not improved considering that take a look at driving the car prior to buying it. Because August 2003 I have clocked effectively around 20,000 miles -as of 1/18/2005- and I have but 1 ounce of regret about my determination. If you would like to browse much more about owners’ views, go to this thread @ RX8Club.com

There have been a amount of European “updates” introduced for the duration of the previous 2 many years. To the finest of my knowledge, all early samples of ’04 RX-8s, arrived from port with amount “J” of engine administration software package. Because then, we have escalated all the way as a result of the alphabet to “M” -which was released on a TSB campaign by Mazda North The united states (MSP04) in get to have ALL autos taken in for Company @ Approved Dealers flashed to “M” calibration.