If there is any justification for Mazda's claim to being the brand of "zoom zoom" driving, it is the RX-8 coupe. With its tiny rotary engine, chiseled exterior profile, and racing heritage, the RX-8 is an attractive and individual package that competes with cars above its price range.
Not much has changed in the drive train, exterior styling, or cabin tech of the RX-8 since its launch in 2004. Besides a slight reduction in power (the current model's 1.3-liter Renesis twin rotor engine delivers less horsepower than its '05 predecessor) and a new color scheme, the swoopy coupe has, like Honda's S2000, rested on its deserved laurels without any major upgrades. (An updated 2009 model of the RX-8 is scheduled to be unveiled at next month's Detroit auto show, we hear.)
On the downside, this lack of drawing-board action has meant that the basic cabin electronics that were looking dated when they emerged in 2004 (was anyone still using minidiscs, even then?) now look antique. Without many tech toys to entertain us for our weeklong review, we did what we always do in these situations: we got out our performance computer and found a long, straight piece of road.
Test the tech: Rotary racing
Having driven the RX-8 around for a few days, we realized that, despite the car's obvious sporty character, there was a conspicuous lack of power at the low end of the rpm range--attributable primarily to the small displacement of the rotary engine. We often found ourselves pulling off from a stop, burying our foot into the gas pedal, and waiting at least a couple of heartbeats until the rpms wound up to a sufficient speed to translate into any notable acceleration.
With this in mind, we set about a challenge that would require us to get the maximum out of the engine at low speeds. What better test, we figured, than running some 0-to-60 tests, experimenting with different throttle input strategies to get the most out of the engine?
The RX-8 is available with a six-speed automatic transmission, which, in addition to putting an extra $700 on the sticker price, reduces the car's maximum power (212 horsepower), the redline, and the overall amount of fun you can have with the car. Thankfully, our tester didn't have it. Instead, we got a close-ratio six-speed manual box, programmed by a delightful short-throw shifter.
Prior to our test, the ground had been dampened by a recent rainstorm, so we were going to have to deal with a slight lack of traction when launching. Nevertheless, we threw caution to the wind and removed dynamic stability control to ensure that we didn't get any unsolicited "help" from the car. The task that faced us was clear: load the rotary engine with enough rpm to give us a brisk start without overdoing it, ending up stationary in a cloud of rubber smoke.
Dropping the clutch at 9,000rpm is not advised.
On our first run, we wound the engine up to about 3,500rpm and dropped the clutch, resulting in a lot of screeching and a lack of traction before the car lurched forward and then appeared to take an age to get up to a decent rate of acceleration. The performance computer clocked the run at 6.77 seconds, and we knew that we could do better.
On the second run, we reduced the rpms to about 3,000, dropped the clutch, and buried the gas pedal as soon as the wheels gained traction. The result was a slightly quicker (though not spectacular) 6.73, but we figured that if we could eliminate the wheel spin, we could shave some time off.
The next run was the best of the day: loading the engine up to between 2,000rpm and 2,500rpm, we dropped the clutch, got immediate traction, and rapidly fed in the power: we held first gear right up to the 9,000rpm redline, when we were notified by the car's shrill beeping noise that it was time to shift up into second gear.
The difference between the low end of the rpm range and the top end (peak power is at a stratospheric 8,500rpm) is remarkable, and by the time we arrived at 60mph, it felt like we could have continued on to 120mph in half the time. We clocked the run at 6.72 seconds--the best that we could do, but not the kind of performance we'd expect from a piston-engined car in the same segment.
In the cabin
One of the most remarkable things about the cabin of the RX-8 is how to get into it. Unlike other "2+2" models such as the Jaguar XK and the Mitsubishi Eclipse Spyder, the RX-8's rear seats are actually accessible, albeit only to children and sub-5-footers. The reason for this distinction is the RX-8's innovative variation on suicide (Mazda calls them "freestyle") doors.
The trick that enables a car of the RX-8's compact size to incorporate such doors is its absence of a B-pillar, which is replaced by the rear-hinged back door. For this design to work, the back door has to be closed before the front door (which latches to it, as it would to a B-pillar). The one drawback to this design is that those in the backseat cannot get in or out without opening the front door. But at least they can get in and out at all.
The RX-8's freestyle doors allow easy access to the rear seats.
Another notable feature of the RX-8's design is the prevalence of triangular symbols inside and out: a reference to the engine's three-sided rotor, these devices adorn the headrests, the gear shifter, and even the top of the hood, giving the cabin a slightly Masonic feel. Our car also came with the optional "rotary accent package," which includes two polished badges of the same shape attached underneath the front and rear bumpers.
If the RX-8 is a car for sports car purists from the outside and under the hood, then it is even more so in the cabin, as there are precious few gadgets to tempt the driver's eyes from the road. For entertainment options, our top-of-the-range Grand Touring model came with all the RX-8 has to offer in the form of a highly stylized stereo head unit with black-piano lacquer finish. (The number of pianos that give their lives each year to furnish Mazda interiors does not bear thinking about.)
The standard audio system comprises an in-dash, six-disc changer without the ability to read MP3 or WMA discs. From the evidence of a redundant button on the right of the stereo, it appears that the RX-8 may have once offered tape deck and even minidisc playback capabilities. While the trip down music format memory lane was pleasant, however, we would like to have seen at least an auxiliary input jack for hooking up our iPod.
One more piano bites the dust.
Our car did come with the Sirius Satellite Radio option ($438), which gave us an alternative to Red Book CDs and AM/FM stations. However, as we found in our review of the MazdaSpeed 3, Mazda's designers don't appear to test the integration of satellite radio in their navigation-lacking models. If they did, they would see that the means of selecting stations is far from intuitive.
While it is possible to call up the name of the current channel--and current artist--on the monochrome LCD screen above the dash by pressing the DISP button, it is not possible to change that channel without reverting to the channel number. You can then search for other stations only by number, calling up the text for the channel name only by further pushes of the DISP button. If you're anything like us, you probably don't know all 134 Sirius stations by number.
Somewhat surprisingly, the RX-8 does come with GPS navigation as an option: for an extra $2,000, drivers get a voice-activated navigation system with a 7-inch touch screen that pops up out of the top of the dash. According to Mazda, the navigation system's touch screen can also be used to program the car's climate control and audio systems. In the absence of the navigation system, however, we were reduced to using the RX-8's head unit controls to program our music selection.
Our test car did not come with the optional touch-screen navigation system.
Under the hood
As noted above, the real story with the RX-8 is its Renesis rotary engine, which is the only one of its kind currently in production. It works by replacing the pistons, valves, and other reciprocating parts of a regular internal combustion engine with two chambers, each containing a three-sided rotor orbiting a central axle.
As the rotors spin in their respective chambers, they create a constant cycle of suction and compression between their apexes and the chamber housing. This action sucks the fuel-air mixture into the combustion chamber, where it is sealed, compressed, and ignited by two spark plugs.
The power created by the ignition of the fuel is translated to the gearbox via offset (or "eccentric") lobes on the output shaft. As the rotor spins around the chamber, it pushes on the lobes, which, in turn, cause the output shaft to spin. (For a good visual impression of how it works, check out Mazda's video.)
It's in there somewhere.
Due to its unique mechanism, the Renesis engine is far smaller--and therefore has need of less displacement--than a comparably powered piston engine. Not only does this save weight, it also enables the engine to be mounted aft of the front axle, adding to the RX-8's near 50-50 front-to-rear-weight distribution. This balance, combined with an as-standard limited-slip differential, gives the RX-8 the kind of superior handling and road-holding prowess that invites spirited misbehavior.
The lack of moving parts in the rotary engine relative to piston engines also ensures a noticeably smoother ride. When driving around in the RX-8, we found the usual judder associated with manual up- and downshifts in piston-engined car.
As we saw in our 0-to-60 mph runs, the RX-8 can feel anemic off the line and through the lower rpm range, but once you have the ground speed and engine speed up, it is a delight to drive, especially when changing down for quick acceleration and holding gears all the way to redline, which results in a melodious growl from the exhaust.
The downside of all this fun is the RX-8's pitiful gas mileage, which results principally from the inefficiency of the rotary engine, compared with piston-power plants. We managed just more than 220 miles on a full 16-gallon tank of gas, translating to a meager 14 mpg, nearly half of which was in highway driving. (We can't even blame this poor fuel economy on our 0-to-60 runs, which we did after refueling).
From its distinctive exterior styling to its unique rotary engine, the Mazda RX-8 is a mold breaker. It is in serious need of a cabin tech upgrade, and its gas mileage would be disappointing for a piston engine car with three times as much displacement.
Stoplight speed demons will also be put off by its lack of low-end oomph. But there is more to spirited driving than shredding tires, and the RX-8's precise handling and high-revving engine are a joy. It might not win over Ford Mustang fans, but those looking at the Nissan 350Z and the Mitsubishi Eclipse Spyder might want to consider this zoom-zoomer as an option.