Yes, you read that right. Cadillac once took a large plush luxury sedan and gave it more horsepower than any of the most desirable sports cars on the market at the time. Let’s not forget the Cadillac STS-V!
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There is an ongoing trend at Cadillac. Every now and then the brand releases a wild model that you can’t believe has been approved by GM’s bean counters. Then it just disappears. That’s exactly what happened to the STS-V, which on paper looked like it could be America’s answer to AMG, M and RS.
The STS-V came to Cadillac just two years after the introduction of the V Performance brand. This was the era of the first-generation CTS-V, with Corvette LS power and a six-speed manual transmission. The CTS-V proved to be a credible threat to the BMW M3, among others. But to be taken seriously, Cadillac needed more Vs.
So in 2005, Cadillac shocked everyone with the introduction of one of the most expensive vehicles GM had ever offered: the Corvette-based XLR and the high-quality XLR-V.
The XLR-V had quite a interesting engine choice. Rather than go for a version of the small block V8 found in its platform companion, the Corvette Z06, Cadillac had to be “brand-exclusive.” So the automaker threw a supercharger on top of the 4.6-liter Northstar V8, resulting in a then-impressive 443 horsepower and 413 lb-ft of torque. But Caddy’s V division wasn’t done yet.
Cadillac turned its attention to the favorite luxury sedan of dads with a taste for the finer: the STS. I am not exaggerating: JD Power has published a study in the early 2000s, showing that the average Seville/STS buyer was 58 years old. That was the second oldest buyer in Cadillac’s lineup, and an aging customer base was a problem for GM as a whole — of the top 10 cars with the oldest average buyers on JD Powers’ list, seven were GM products.
So Cadillac needed a way to attract younger customers, especially those interested in German sports sedans. The timing was perfect: The STS (“Seville Touring Sedan”) had just been completely redesigned for 2005, moving to the rear-wheel drive Sigma platform shared with the CTS and SRX crossover. And while you could get the regular STS with a 320 horsepower version of the Northstar engine, that wouldn’t lure BMW buyers away.
Cadillac had its V engineers lay their hands on the new STS. It got wider tires, 255/45R-18s in the front and 275/40-19s in the rear; they were Pirelli run-flats, as the larger wheel-and-tire package didn’t fit a spare in the trunk. The STS-V got the same 14-inch Brembo brakes that provided the stopping power of the CTS-V. The front dashboard got larger air intakes with mesh grilles, and the hood got a powerful bulge to accommodate the supercharger. In the back there was a small rear spoiler along with some changes to the underside that increased the drag coefficient by 0.01, all in the name of stability at high speeds. Inside, the biggest changes were sports seats with suede inserts and a more “luxury” dashboard with studded trim all around.
While all the fast and luxurious looks were cool, the big news was under the hood. Cadillac hit a supercharger and delivered a 12-pound boost on top of the Northstar V8—basically a slightly smaller Northstar. A bore of two millimeters (from 93 to 91 millimeters) reduced this engine from 4.6 liters to 4.4. Along with the supercharger, a boosted cooling system combined with a low intake and exhaust resulted in 469 horsepower, 26 more than the XLR-V, and 439 lb-ft of torque. That’s more power than the 455 hp 996 Porsche 911 Turbo from the same year, a legend among sports cars. And the Cadillac had more power than most of its sports sedan competitors: the Audi RS 6 had 450 horsepower from its twin-turbo V8; the Jaguar S-Type R had only 390 horsepower. The only sports sedan to match the Caddy was: the Mercedes CLS 55 AMGwhich had exactly 469 horsepower.
To handle all that new power, Cadillac engineers installed an all-new six-speed automatic transmission and beefed up the front and rear suspension. The result was a heavy (4,376 lbs) but fast American sedan. It could run to 60 mph in just 4.8 seconds.
All this, of course, was not cheap. The price started at $77,090, one of the most expensive cars in Cadillac’s lineup and at the time at GM.
The STS-V is surprisingly rare these days. From 2006 to the shutdown in ’09, only 2,440 were made. They’re pretty cheap now if you can find one: at the time of writing, I found one for sale for just over $13,000. And if the owner forums are to be believeddespite the known problems with the Northstar engine itself, STS-Vs didn’t seem to have too many major engine problems.
Cadillac now produces two of the most powerful and capable sports sedans on the market today. While you may not have thought of the STS-V in a while, it’s clear that today’s Cadillac V performance line owes something to the wildness of an American sedan that had more power than a 911 Turbo all the way back in 2006.