'97 BMW 540i

Early this year, BMW wowed the press and public alike when it unveiled the all-new 528i, illustrating how careful planning and creative engineering could make the 5-Series bigger and better without increasing cost, weight, or fuel consumption. Now, with the introduction of the uplevel 540i, BMW once again has sparked the debate over which model is truly the Ultimate Driving Machine.

By starting with a platform that's basically a morph of the 7-Series and previous 5-Series, then basting it with spicy engineering flavor, and finally giving it a quick microwave melt to round out the edges, Olympic sponsor BMW has created both a world-class sprinter and long-distance runner in the 540i.

The heart of this performance sedan is a 4.4-liter/282-horsepower DOHC V-8 engine derived from the previous 4.0-liter powerplant. Torque has increased throughout the powerband, particularly at lower rpm, for improved acceleration from a standstill, through traffic, and on hilly roads. This was accomplished by increasing displacement via a 3.0-millimeter-larger bore and a 2.7-millimeter-longer stroke, creating the richer torque curve. Improvements to the valvetrain, camshafts, heads, and electronic management system contribute to reduced internal friction and improved engine efficiency. Peak horsepower remains unchanged, but the maximum torque output has risen from 295 at 4500 rpm to 310 at 3900 rpm. As an added bonus, the aluminum engine complies with the strict California emissions standards and avoids the gas-guzzler tax when mated with an automatic transmission.

Diverging slightly from the 528i, the 540i essentially adopts the 7-Series front end with a tubular steel subframe, rearward lower transverse arm that serves as a compression strut, and recirculating-ball power-assisted steering system for a more luxurious feel. Unlike the 7-Series, both 5-Series models make extensive use of cast aluminum pieces for weight savings in the front and rear suspensions.

Similarly, the rear suspension design on both 5-Series models is carried over from the Seven, but is executed in aluminum. The reduction in unsprung weight allows the suspension to react more quickly to changing driving conditions, thereby improving both the ride and handling-an advancement that became quite apparent as we tore through rural streets on the outskirts of Munich, Germany. The 540i's ride remained compliant as rough, uneven pavement was reduced to ripples, and tight switchback turns were handled with balance and confidence.

When equipped with the precise-shifting Getrag six-speed manual transmission, the 540i features a Nrburgring-ready M-Technic sport suspension, much like that of the previous model year, making this car as close to an M5 as any factory Bimmer you can buy.

Larger anti-lock brakes accompany the bigger V-8 engine, with 12.8-inch vented discs up front and 11.8-inch vented discs at the rear. The automatic-equipped 540i rolls on 16x7.0-inch 20-spoke aluminum wheels surrounded by Pirelli P6000 225/55HR16 tires, while the six-speed manual version features larger 17x8.0-inch two-piece seven-spoke wheels and aggressive 235/45WR17 tires.

Incredibly, despite its overall size increase and additional standard equipment, the new 540i automatic, at 3803 pounds, weighs exactly the same as its predecessor. However, performance gains are limited: The factory predicts an improvement of 0.1 second for the 0-60-mph run with either transmission. Based on our last 540i six-speed test, that means the new car would blast from zero to 60 mph in 6.1 seconds.