Yes, you read that right. Cadillac once took one big, 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!
Welcome to Forgotten Cars, where we delve into the history of fascinating vehicles that you probably haven’t thought about in ages. Join us on an automotive trip down memory lane.
There is an ongoing trend at Cadillac. Every so often 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 with the STS-V, which on paper seemed like it could be the American answer to AMG, M and RS.
The STS-V came out just two years after the introduction of the V performance brand to Cadillac. 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, for example. But to be taken seriously, Cadillac had 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 a rather interesting engine choice. Instead of going with a version of the small block V8 found in its platform mate, 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 an impressive 443 horsepower and 413 lb-ft of torque for the time. But Caddy’s V Division wasn’t done yet.
Cadillac turned its attention to the favorite luxury sedan of dads with a penchant for finer things: the STS. I am not exaggerating: JD Power published a study in the early 2000s which showed 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 received a complete redesign 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 couldn’t fit a spare wheel in the boot. The STS-V got the same 14-inch Brembo brakes that provided the stopping power on the CTS-V. The front panel received larger air intakes with mesh grilles and the hood was given a powerful bulge to accommodate the supercharger. At the back there was a small rear spoiler along with some changes to the underside that actually increased the drag coefficient by 0.01, all in the name of high speed stability. Inside, the biggest changes were sports seats with suede inserts and a more “luxurious” dash with burl wood trim all around.
While all the fast and luxurious looks were cool, the big news was under the hood. Cadillac slapped a supercharger and made 12 pounds of boost on top of the Northstar V8—basically a slightly smaller Northstar. A two millimeter bore reduction (from 93 to 91 millimeters) reduced this engine from 4.6 liters to 4.4. Along with the supercharger, a strengthened cooling system along with a low-restriction intake and exhaust resulted in 469 horsepower, 26 more than the XLR-V, and 439 lb-ft of torque. That’s more power than that 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 sport-sedan competitors: The Audi RS 6 had 450 horsepower from its twin-turbo V8; the Jaguar S-Type R had only 390 hp. The only sport 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 strengthened the front and rear suspension. The result was a heavy (4,376 lbs) but fast American performance sedan. It could run to 60 mph in just 4.8 seconds.
Of course, all this was not cheap. The price started at $77,090, one of the most expensive cars in Cadillac’s lineup and at GM at the time.
The STS-V is surprisingly rare these days. From 2006 to its discontinuation 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 .