2006 Mazda Miata By Jim McCraw, New Car Test Drive .com

One of the most eagerly awaited cars introduced at this year's Geneva Auto Show was the 2006 Mazda Miata, known over there as the MX-5. The 2006 version is the most heavily modified design since the car was introduced in 1990, far more radical than the 1999 facelift.

When it goes on sale this summer, the all-new 2006 Mazda Miata promises more comfort, stronger acceleration, better handling and better braking.

The new Miata body shell is larger, longer, sleeker and more racy than the previous designs, with flatter flanks and pronounced wheel arches like the RX-8, new integrated headlamps, a completely new hood and front fender look, and a cleaned-up tail end appearance.

The new unibody delivers an increase of 22 percent in bending stiffness and 47 percent in torsional rigidity compared to the previous-generation Miata. The wheelbase is 2.6 inches longer, a substantial increase, but overall length has increased by less than an inch (0.8 inches), resulting in shorter overhangs for better handling. It's width has been increased 1.6 inches, and the height is up 0.8 inches. Another major change is a 3-inch increase in front track and a 2.1-inch increase in rear track, for improved handling. In short, the wheels have been pushed farther out toward the corners of the car, a significant engineering improvement.

It's a roomier car than before. Inside, the new Miata is more accommodating for larger American drivers, with new sport bucket seats that have integrated thigh and shoulder bolsters. Rearview mirrors have been relocated for easier viewing. Seat travel has also been increased to better fit taller and shorter drivers.

Side air bags will be optional for the first time on Miata. For the first time, the Miata will come with a multi-function adjustable steering wheel with audio system controls built in. A major concession to American buyers are two central cupholders in the console and one more integrated into each of the door panels. The new five-gauge dash has polarized glass covers for easy reading in bright sunlight, and relocated air vents for more comfort when driving with the top down in hot or cold weather.

Underneath, the Miata chassis shares a number of brake and suspension components with the RX-8, including a double-wishbone front suspension and multi-link rear suspension system. With all the new features, curb weight has only increased by 22 pounds, with most of that increase accounted for by the new 16-inch wheels and tires that come standard; 17-inch tires and wheels will be optional in two wheel designs.

Front brake rotors are 0.8 inches larger in diameter and calipers are 25 percent stiffer. Brake hoses are stiffer, and the power booster is one inch larger.

The engine for the new Miata is a new all-aluminum double-overhead-cam, 4-valve 2.0-liter, up from 1.8 liters, sporting a larger bore, and shorter stroke, higher compression of 10.8:1, variable intake valve timing, and electronic throttle control.

The new engine is expected to produce 170 horsepower at 6500 rpm and about 140 pound-feet of torque at 5000 rpm. That's a significant increase in power over the current engine, which is rated at 142 horsepower at 7000 and 125 pound-feet of torque at 5000 rpm. The engine has a lighter flywheel for easier revving. The engine was moved rearward in the chassis by a whopping 5.3 inches, a major step for front-to-rear weight distribution. The transmission is a new 6-speed manual.

The convertible top is a Z-fold design with a single central latch handle that opens and closes with a quarter turn. In the lowered position, it fits flush with the body, without a tonneau cover. The top can be raised or lowered by hand from the driver or passenger seat. A new detachable hard top with more rear glass angle for a better top-on look is also available.

Mazda officials were reluctant to predict the U.S. prices, but said that they will be within a few percent of current prices.