2005 Cadillac STS Road Test

This is quite a functional driver's aid, especially for those who routinely log many highway miles. When the slower traffic

The Intellibeam HID headlamps automatically dim the high beam lights when another vehicle is approaching or when a set of taillights is detected. (Photo: Rob Rothwell, American Auto Press)

departs, the adaptive cruise control system returns the STS to the preset speed. I enjoyed using this feature, which can be disconcerting the first time the Caddy comes up on a slower vehicle, but trust me, it works.

Worthy of further explanation are the Intellibeam HID headlamps. These units automatically dim the high beam lights when another vehicle is approaching or when a set of taillights is detected. Once the interfering light source departs, Intellibeam automatically returns to a high beam setting. I tested this system around town and was quite astonished by how effectively and reliably it lived up to expectations.

Also working well is the STS' remote starting feature, which Cadillac calls "adaptive start." From 200 feet away, the key fob will fire up the STS and recall the

My tester was equipped with the 4.6 liter, DOHC 32-valve 8-cylinder powerplant. (Photo: Rob Rothwell, American Auto Press)

memory settings for the driver's seat, steering wheel, outside mirrors, radio and HVAC controls. If not started remotely, the STS senses the presence of the key fob and unlocks the doors. But don't bother looking for an ignition slot, there isn't one. When the fob is within proximity, such as in a pocket or purse, pressing a dash-mounted button ignites the STS and recalls the settings specific to the particular fob.

Once juice has been ordered, either a 255 horsepower V6 or a 320 horsepower V8, both equipped with variable valve timing technology, will discreetly burst into life. My tester was equipped with the more muscular of the pair. Displacing 4.6 liters, the DOHC 32-valve 8-cylinder powerplant also generates 315 pound-feet of torque at 4,400 rpm.