All-new for 2005, the Cadillac replaces the 2004 Seville. Along with the all-new styling, everything is different on the underside as well; based on GM’s Sigma architecture, which it shares with the CTS sedan and SRX wagon, the STS is rear-wheel-drive to the Seville’s front-wheel system. It also offers all-wheel-drive, a first for a Cadillac passenger car. It’s a real system too, driving all four wheels, all the time.

Two engines are available, a 3.6-litre V6 and a longitudinal-mounted 4.6-litre Northstar V8. Both hook up to a 5-speed Hydra-Matic automatic transmission. Currently AWD is only available on the V8, although it’s expected on the V6 for 2006. The STS also comes with Cadillac’s award-winning Magnetic Ride Control, and with StabiliTrak.

Both models contain all the expected luxuries: the V6 includes fog lights, dual projector beam headlights, heated power mirrors with driver’s side auto-dimming and passenger side parking tilt-down, 17-inch painted aluminum wheels with V-rated tires, automatic dual-zone electronic climate control, cruise control, auto-dimming rearview mirror with three-button OnStar, leather-wrapped wheel, power tilt and telescopic wheel, front and rear express up/down windows, heated leather seats with eight-way power driver’s seat and four-way power passenger seat, rear-seat pass-through, CD/MP3 player with eight speakers, wiper-activated headlights and rear parking assist. A starter button, dropped by Cadillac for 1951 in favour of the "modern" key ignition, is back in vogue and standard on the STS.

The V8 contains the same features, while adding 17-inch S-rated tires, air filtration system, rear air conditioning controls, three-channel garage door opener, luggage net, memory seating, heated steering wheel, wood accents, front and rear heated seats, and six-disc CD/MP3 system.

Available STS options include power sunroof, polished aluminum wheels, adaptive cruise control, premium Tuscany leather seats and a performance brake package.

Cadillac wants to reestablish itself as the "Standard of the World", and it’s going in the right direction. The angular styling introduced on the CTS works well on this bigger canvas, and the interior is very well done, with real eucalyptus wood instead of that from plastic trees. The seats are long-haul comfortable, although the rear seat room is tighter than expected. Both the V6’s load-leveling air shocks and the V8’s Magnetic Ride Control make for flat cornering and a smooth trip over the bumpiest roads. This is a luxury sedan that you can take through the twisties with confidence. "World-class" is an overused phrase, but it definitely applies here.

The STS is built in Lansing, Michigan.

Connect with Autos.ca