2010 Cadillac STS
Expert Review

The revamped 2008 version of Cadillac's sporty import-fighting STS sedan comes closer to rear-wheel-drive rivals such as the costlier BMW 5-Series and Mercedes-Benz E-Class.

The STS look bolder, with a larger shiny grille, chrome door handles and functional chrome front fender vents, which let heat escape from the engine compartment.

My test STS had $995 Thunder Gray Chromaflair Premium Paint, which slightly changed color under different lighting conditions. That nifty paint would be extravagant for lesser cars, but not for the premium STS.

The new STS has an improved interior with a new steering wheel and such items as supple leather, elegant wood and metal with a sporty metallic appearance.

Major New Engine
The major news is a 3.6-liter V6 that kicks out 302 horsepower. It provides nearly the acceleration of the STS 4.6-liter V8, which produces 320 horsepower. That V6 is one of General Motors' most potent V6s ever, and Cadillac predicts that most STS buyers will opt for this engine, which was in my test STS.

The V6 provides 47 more horsepower than the 2007 V6 of the same size largely because it has variable intake and exhaust valve timing and direct fuel injection. Such injection squirts gas into the combustion chamber rather than an intake track leading to that chamber. The fuel produces a cooling effect that reduces the tendency for engine "knock" and allows the compression ratio to be raised—in this case to a sky-high 11.3:1—for more power and fuel economy.

Higher V6 Fuel Economy
The STS with the V6 does 0-60 mph in 6.5 seconds, which makes it almost as fast as the STS V8. The V6 needs only 87-octane gas and delivers an estimated 17 mpg in the city and 26 on highways. (Ratings would be a few mpg higher using the 2007 EPA fuel economy rating procedures.) The V8 needs premium fuel and provides an estimated 15 city and 24 highway.

An awesome supercharged 469-horsepower V8 is offered in the limited-production STS-V, but that trim level is offered because rival European automakers offer mega-horsepower engines.

All engines shoot power through a responsive 6-speed automatic transmission with a manual shift feature.

Lower Cost V6
The STS V6 has a $42,390 list price, while the V8 costs $51,810. The STS-V is $76,555. All are well-equipped with many comfort, convenience and safety features, including front-seat side airbags and side-curtain airbags.

While STS V6 and V8 trim levels have standard rear-wheel drive, just like their European competitors, they can be had with an optional all-wheel-drive system, although the STS has standard stability and traction control systems.

Other options include an overly sensitive lane departure alert feature that beeps if the STS moves into another lane when a driver doesn't signal a lane change with the turn signal and a Premium Luxury Collection package that has a navigation system and power sunroof.

A Luxury Performance package contains a bunch of items such as heated/ventilated front seats and heated rear outboard seats and steering wheel, wider tires on larger 18-inch polished aluminum wheels, upscale Bose sound system and a discreet rear spoiler.

A Premium Luxury option's items include a blind-spot alert system and head-up display that projects speed and other functions on the windshield and makes it easy to keep track of the car's speed without the need to look down at the regular speedometer.

A Top Option
One of the best extras is the Performance Handling Package, which has gorgeous 18-inch chrome aluminum wheels with extra-wide 45-series summer-only tires and Brembo brakes, also used on exotic sports cars.

That package also contains a sport suspension and retuned steering with an especially good power assist feature. The STS has good ride and handling with its standard suspension, but roadability is sharper with this option, which really should be standard.

Push-Button Mishap
The push-button engine starter/stopper on the dashboard can be convenient. But one must push the small stop engine section of the button firmly and precisely to shut off the engine. Otherwise, the quiet engine won't turn off and will continue idling. That happened to me during a lunch stop, and the engine wasted gas for about an hour when idling.

Another flaw: Power window controls on the driver's door make it easy to accidentally lower the left rear window when you want the left front one opened.

On the flip side, it's easy to get in, with large outside handles and wide-opening doors. Dashboard gauges can be quickly read, but my test STS had an awful lot of dashboard buttons.

Some of those buttons had vague markings, and the owner's manual didn't fully explain some of their functions, although it was thick.

Roomy Interior
The quiet, upscale interior has supportive front seats, and there is good room for four to five 6-footers. All cupholders are conveniently located, and the front ones have a sliding cover. Doors have storage pockets, and the console bin is deep.

The large trunk has a low, wide opening, although it's rather small and thus limits the size of items that can be easily loaded. Its lid raises on struts that don't eat into luggage space.

The hood raises on a strut, revealing an engine compartment with some fluid filler areas that must be reached from the side of the car.

The new V6 is the best engine for most STS buyers, but some may find it hard to picture this sporty Cadillac without a V8.