BMW has made small improvements throughout the 5-series, but the real news is not the relocated window switches. It’s the revised six-cylinder engines. That’s why we were summoned to Las Vegas to take our turn behind the wheel of each new model (528i and 535i), as well as the mechanically unchanged 550i and M5. To read more about the mini-Gumball-like rally, click here. To read about the cars and engines, you’re already in the right place.

The 3.0-liter twin-turbo inline-six powering the 535i is the headliner of this mid-cycle makeover, a massive improvement of 45 horsepower and 80 lb-ft. of torque over the engine it replaces. In the 335i, we found this motor to be a smooth and torquey dream.

Shouldered with a couple hundred extra pounds in the 5-series, the twin-turbo 3.0-liter’s delights are only slightly diminished. After driving all varieties of 5-series, this is the car that was unanimously voted the best buy. The 200 pound weight-savings over the more powerful 550i results in a car that feels more balanced, with a sportier feel and greater willingness to engage and conquer corners on the roads snaking down toward Death Valley’s floor, 282 feet below sea level. Even better, the 535i should be good for scampering to 60 mph in the mid-to-high five-second range, nearly running with the far more expensive 550i.

As delightful as the engine and ride are, the car is not perfect. Although nicely weighted, the schizophrenic steering is curiously twitchy and numb just off center. Once the car is bent into a turn, confidence builds, but when traveling in a straight line, the car nervously feints after every irregularity in the road. Placing the car near the outside stripe on the pavement takes more faith than it should. This, of course, is a problem present in all 5-series models, regardless of engine choice.

An additional steering problem you can now buy from BMW is an unexpected vibration in the steering wheel, like driving over a mild rumble strip. Consider it the preamble to a rumble strip, as that vibration is the tactile feedback from the lane-departure warning system, a solution that doesn’t alert your friends to your woozy driving but is far more unsettling. We’re about as happy to see this option in the 5-series as we were when that headache iDrive first came out.

source:caranddriver

This entry was posted on Friday, May 25th, 2007 at 11:40 am and is filed under Car Models [t], Car Reviews [t]. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.