Sports cars are usually about great handling, light weight, and, generally, selfish proportions. They're not about needs and practicality. Rear seats, let alone rear doors, add power-sapping, balance-mucking heft. No matter, Mazda will give the four-door sports-car concept a go with its new, rotary-powered RX-8.
The RX-8 rear-seat area has enough leg and elbow room for a trip to an out-of-the-way restaurant, although headroom is a bit tight. Its framed, pillar-free doors offer a big opening, like those of a Saturn Ion, although the RX-8's thick door frames break up clean, muscular lines. At 2933 pounds, this car weighs about the same as the last RX-7; an innovative and light "virtual center pillar" adds safety. Steel pipes under the aluminum skin of the rear doors connect to a brace via strong door latches. Catchpins in the front and rear doors help pass side impact to the underbody. With a high-backbone frame and a stiff chassis, the automaker expects top crash-test ratings in all world markets, while the rear doors give Mazda a unique feature it believes necessary to carve a niche in a crowded sports-car market.
Renesis is the name for the latest version of Mazda's trademark Wankel rotary engine, pegged at 250 horsepower in the six-speed manual RX-8.
Mazda also developed a new Wankel rotary engine, dubbed the Renesis, with improved emission and fuel-economy levels. The biggest change from the old RX-7 rotary to the Renesis is the relocation of the exhaust ports to the side of each rotor chamber. The old rotary's exhaust ports overlapped the intake port opening, making it difficult to burn exhaust that snuck into the intake. The Renesis has no such overlap, so the fuel-cycle's air is clean and the intake exhaust is carried to the next process and reburned. Mazda says this means less fuel consumption for about the same power as the old turbo RX-7: an estimated 250 horsepower in the six-speed manual version. The four-speed automatic gets a slightly detuned, 210-horsepower Renesis. Mazda predicts an EPA fuel-economy rating of 18-19 mpg city and 23-24 highway.
The RX-8's suspension is fairly sophisticated, but uses more steel than aluminum. The 210-horse automatic version comes standard with 16-inch wheels and tires suspended by double wishbones. The sport suspension, standard with the 250-horsepower stick-shift model, stiffens the shocks and springs and upgrades the rolling stock to 18 inches. New electronic power rack-and-pinion steering is light and precise, but lacks feedback compared to mechanical rack-and-pinion systems.
While Mazda says its target is better ride comfort and less body movement compared to the Honda S2000 and its own RX-7, the RX-8 may not be as knife-edge sharp and sports-car purposeful as the new Nissan 350Z. Through the tight esses of the 2.1-mile Miyoshi Proving Ground's Global Circuit, the RX-8 prototype we drove demonstrated mild initial understeer and moderate body roll. Slalom through quickly enough, and the outside rear tire hunkers down as the tail slides slightly (our sample car didn't have the optional stability control). It reminds us of the first RX-7 with its controllable power-throttle oversteer and 50-50 weight distribution.
The RX-8 is comfortable and stable over bumpy surfaces. And it's a quiet chassis, with only the turbine-like whine of the rotary at high revs to remind you of its sporting purpose.
The Renesis sits 1.6 inches lower and 5.5 farther back behind the front wheels, compared with the last front mid-engine RX-7, for better balance and yaw inertia. If we have one early observation, it's that the RX-8 is no torque-monster, especially at the lower end. But its nicely balanced handling, combined with an engine that winds up evenly to its 9000-rpm redline, make the RX-8 is an easy sports car to drive. If you've been behind the wheel of a first-gen RX-7, you'll feel at home.
Tags: Automobiles Transport