The sporty STS long has been Cadillac's European-oriented mid-size sedan, although the revamped 2008 version comes closer to such rear-drive rivals as the costlier BMW 5-Series and Mercedes-Benz E-Class.
The nicely styled STS looks bolder, with items such as a larger glittering grille, chrome door handles and chrome front fender vents. Such vents are becoming popular, but most are fake. The STS vents are functional, allowing heat to escape from the engine compartment.
My test STS had unique $995 "Thunder Gray Chromaflair Premium Paint," which changed color a bit under different lighting conditions. It sounds extravagant, and probably would be for a lesser car.
My test STS had unique $995 "Thunder Gray Chromaflair Premium Paint," which changed color a bit under different lighting conditions. It sounds extravagant, and probably would be for a lesser car.
The new STS has an upgraded interior with a new steering wheel and such items as supple leather, elegant wood and metal with a sporty metallic look.
But the big news is a 302-horsepower 3.6-liter V-6. It provides nearly the punch of the STS 4.6-liter V-8, which has 320 horsepower. The V-6 is General Motors' most powerful production V-6 ever. Cadillac predicts that most STS buyers will opt for this engine, which powered my test STS.
The V-6 is a stop-your-breath example of engineering. It provides 48 more horsepower than the 2007 same-size version, 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 for more power, efficiency and fuel economy.
The new V-6 thus has a sky-high 11.3:1 ratio -- not even found on some famous 1960s muscle cars, which guzzled 100-plus octane leaded gas. The STS V-6 does 0-60 mph in 6.5 seconds, which makes it nearly as fast as the STS V-8.
The V-6 needs only 87-octane unleaded fuel and delivers an estimated 17 mpg in the city and 26 on highways with the EPA's lower ratings for 2008 cars. (It'd be a few mpg higher using the 2007 EPA formula.) The V-8 calls for premium fuel, and provides an estimated 15 city and 24 highway.
There's an over-the-top supercharged 469-horsepower V-8 in the special STS-V. But that model is offered mainly because rival, horsepower-crazy BMW and Mercedes offer mega-horsepower engines. Economy with the STS-V V-8 is 13 city and 19 highway, and premium fuel is needed.
All engines work with a responsive six-speed automatic transmission that has a manual shift feature.
The STS V-6 lists at $42,390, while the V-8 costs $51,810. The STS-V is $76,535. All models are well-equipped with luxury, comfort and safety items, including front side air bags and side curtain air bags.
Both the STS V-6 and V-8 models have standard rear-drive but can be had with an optional all-wheel-drive system, although the STS has standard stability and traction control systems. All-wheel drive, which is becoming increasingly popular for cars, costs $1,900 for the V-6 STS and $1,550 for the V-8.
Other extras include a lane departure alert feature that beeps if the STS wanders into an adjoining lane when a driver doesn't signal a lane change with a turn signal -- sounds perfect for cell-phone users. It's in a $4,250 Premium Luxury Collection package that also includes a navigation system and power sunroof.
A $5,845 Luxury Performance package contains a bunch of items including 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 rear spoiler.
There's also a $4,250 Premium Luxury option with items including 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 for a driver to look down at the regular speedometer.
One of the best extras is the $1,600 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 Italian sports cars. This package also has a sport-tuned suspension and retuned steering with an especially good power assist feature. Handling of the standard STS is good but is sharper with this option.
The push-button engine starter/stopper on the dashboard can be convenient. But it's easy to not push the small stop-engine section of the button precisely and return to the car to find the quiet engine never stopped during your lunch and has been wasting gas when idling. Also, power window controls on the driver's door make it easy to accidentally lower the left rear window when wanting the left front one opened.
It's easy to get in, with large outside handles and wide-opening doors. Dashboard gauges can be easily read, but my test car had an awful lot of dashboard buttons. Some had vague markings, and the STS owner's manual didn't fully explain some of their functions, although it's thick.
The quiet interior has front seats that are supportive for lively driving on winding roads, and there is good room for four to five 6-footers. The center of the rear seat isn't stiff and hard, as is the case with some cars. Front and rear cupholders are conveniently located, and the front ones have a sliding cover. All doors have storage pockets, and the center console bin is deep.
The large trunk has a low opening that's wide and a lid that raises on dual struts, which don't eat into luggage space.
The hood easily raises on a single strut to reveal an engine compartment with fluid filler areas that must be reached from the side.
All things considered, the STS with the new V-6 is the best choice for most buyers of the car, although some might find it hard to picture such a sporty Cadillac without a V-8.
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