High-performance American cars typically feel and look powerful. However, there are some notable exceptions that look slow and boring but pack a lethal punch.
For some enthusiasts, there's nothing like an inconspicuous-looking ride that hides a menacing, high-performance engine under its hood.
While the most insane sleepers you'll ever see are built by car nuts who spend huge amounts of money and time to have one, some models out there blend an inconspicuous look with high performance straight from the factory.
Many of the coolest factory-built sleepers of all time were born in Europe during the 1980s and 1990s doning AMG or Alpina badges, but American manufacturers also developed some excellent high-performance cars with subdle looks that I'm betting most of you have forgotten.
For the 1986 model year, Ford launched a new breed of FWD, mid-size sedans, and station wagons called Taurus as well as an upscale versions marketed called Sabre which was sold with Mercury badges.
Three years later, the Blue Oval surprised everyone by launching a high-performance version of the Taurus sedan dubbed SHO. It got its name from the Super High Output (SHO) V6 found under the hood, which was an impressive DOHC, 24-valve unit developed and built in Japan by Yamaha.
Much like the standard Taurus, it looked like an ordinary sedan that average Joes and Janes drove around in. However, it had an overhauled suspension system, and its Yamaha-built V6 delivered a healthy 220 hp. That enabled the sedan to sprint from 0 to 60 mph (97 kph) in 6.5 seconds, similar to what an L98 C3 Corvette could achieve.
It was a breakthrough sleeper that could be had for much less than similar, high-performance sedans from the likes of Mercedes-Benz, BMW, Audi, or Saab, yet it was just as capable.
Unleashed on public roads in 1994, this American factory-built sleeper was the high-performance version of the first-generation Caprice. However, it was marketed using the Impala and SS nameplates, so it had big shoes to fill.
Though it looked much like its plebian sibling, the blacked-out sedan (later available with two additional colors) came with some special features that were typically installed on Caprice versions meant for law enforcement and government agencies.
No, it wasn't equipped with a police radio or siren, but it did receive a sports-tuned suspension with reinforced springs, disc brakes on all four corners, a standard limited-slip differential, and a higher-outp ut electrical system.
Apart from those goodies, the SS was powered by a 5.7-liter (350-ci) LT1 small-block V8, shared with the Corvette and Camaro. However, this version had cast-iron cylinder heads and a milder cam, so it didn't make impressive output figures. The V8 was rated at 260 hp - about 40 hp less than the LT1 with aluminum heads - which might not seem like much today, but back then, it made the SS a legitimate high-performance sedan.
About 650 pounds (295 kg) heavier than its main rival, the second-generation Taurus SHO, it took 7 seconds to reach 60 mph (97 kph) from a standstill, so it was not exactly quick, but even today, it remains one of the coolest factory sleepers ever built in the US.
After a 33-year hiatus, Mercury resurrected the Marauder nameplate as a high-performance version of the fourth-generation Grand Marquis. Based on the Blue Oval's last traditional body-on-frame sedan chassis, which it shared with the Ford Crown Victoria and Lincoln Town Car, the Grand Marquis was the clear-cut favorite upscale sedan for America's grandparents.
In an attempt to draw younger buyers to its dealerships, Mercury unveiled a convertible version of the Grand Marquis at the 2002 Chicago Auto Show and christened it Marauder. While the production version reverted to the traditional four-door sedan body, it retained most of the concept car's performance upgrades. These included a heavy-duty suspension system, bigger brakes, a limited-slip differential, sportier bumpers, side skirts, and bespoke chrome wheels.
Unfortunately, the convertible's 335-hp supercharged V8 wasn't carried over, but the production Marauder did get a 4.6-liter (281-ci) DOHC four-valve version of the Modular V8. Rated at 302 hp, it was the same engine that powered the Mustang Mach 1, and it was enough to propel the sedan to 60 mph (97 kph) from a standstill in 6.9 seconds.
Even if it didn't look much different from the standard Crown Vic or Grand Marquis, the Marauder was a sleeper that felt like a muscle car, particularly in the higher rev range.
In 2005, Chrysler revived its line of full-size, V8-powered, rear-wheel drive luxury sedans, which ended in 1989 when the Fifth Avenue was discontinued.
Apart from the standard models, the 300 range included a high-performance version called SRT8. It was powered by a 425-hp, 6.1-liter HEMI and received some unique interior touches, but on the outside, it looked like the regular 300C. The only upgrades that distinguished it from the standard version were slightly different bumpers and a small SRT8 badge located on the trunk lid.
While it looked like a heavy and underpowered American luxury sedan, the 300C SRT8 was an exciting sleeper that performed like a European sports car. Its chassis benefitted from German engineering since Chrysler was still under the same corporate umbrella as Mercedes-Benz, and thanks to the powerful HEMI tucked under the hood, it could accelerate from 0 to 60 mph (97 kph) in 4.9 seconds.
For the 2003 model year, GM's luxury division introduced the CTS - a mid-size sedan meant to rival similar European models like the BMW 5 Series or Mercedes E-Class. Then, a year later, the high-performance CTS-V was released as an American alternative to the E60 M5 and W221 E 55 AMG.
Under the hood, the CTS-V hid a 5.7-liter LS6 V8 capable of 400 hp, which it shared with the C5 Chevrolet Corvette Z06. That unit was replaced in 2006 with the 6.0-liter L2, but the horsepower rating remained the same.
Apart from the powerful engine that enabled a 0 to 60 mph (97 kph) time of 4.5 seconds, the CTS-V was equipped with various high-performance upgrades. These included a Brembo braking system with 14-inch rotors hugged by four-piston calipers on both axles and a revamped suspension system with higher spring rates and stiffer anti-roll bars.
When it came to exterior upgrades, the CTS-V was easier to distinguish from its standard sibling thanks to wider wheel arches and more aggressive bumpers. Nevertheless, its looks didn't scream high performance. If you saw one in a parking lot, you'd find it hard to believe it was one of the fastest sedans that money could buy.
While the most insane sleepers you'll ever see are built by car nuts who spend huge amounts of money and time to have one, some models out there blend an inconspicuous look with high performance straight from the factory.
Many of the coolest factory-built sleepers of all time were born in Europe during the 1980s and 1990s doning AMG or Alpina badges, but American manufacturers also developed some excellent high-performance cars with subdle looks that I'm betting most of you have forgotten.
1989–1991 Ford Taurus SHO
Three years later, the Blue Oval surprised everyone by launching a high-performance version of the Taurus sedan dubbed SHO. It got its name from the Super High Output (SHO) V6 found under the hood, which was an impressive DOHC, 24-valve unit developed and built in Japan by Yamaha.
Much like the standard Taurus, it looked like an ordinary sedan that average Joes and Janes drove around in. However, it had an overhauled suspension system, and its Yamaha-built V6 delivered a healthy 220 hp. That enabled the sedan to sprint from 0 to 60 mph (97 kph) in 6.5 seconds, similar to what an L98 C3 Corvette could achieve.
It was a breakthrough sleeper that could be had for much less than similar, high-performance sedans from the likes of Mercedes-Benz, BMW, Audi, or Saab, yet it was just as capable.
1994–1996 Chevrolet Impala SS
Though it looked much like its plebian sibling, the blacked-out sedan (later available with two additional colors) came with some special features that were typically installed on Caprice versions meant for law enforcement and government agencies.
No, it wasn't equipped with a police radio or siren, but it did receive a sports-tuned suspension with reinforced springs, disc brakes on all four corners, a standard limited-slip differential, and a higher-outp ut electrical system.
Apart from those goodies, the SS was powered by a 5.7-liter (350-ci) LT1 small-block V8, shared with the Corvette and Camaro. However, this version had cast-iron cylinder heads and a milder cam, so it didn't make impressive output figures. The V8 was rated at 260 hp - about 40 hp less than the LT1 with aluminum heads - which might not seem like much today, but back then, it made the SS a legitimate high-performance sedan.
About 650 pounds (295 kg) heavier than its main rival, the second-generation Taurus SHO, it took 7 seconds to reach 60 mph (97 kph) from a standstill, so it was not exactly quick, but even today, it remains one of the coolest factory sleepers ever built in the US.
2003–2004 Mercury Marauder
In an attempt to draw younger buyers to its dealerships, Mercury unveiled a convertible version of the Grand Marquis at the 2002 Chicago Auto Show and christened it Marauder. While the production version reverted to the traditional four-door sedan body, it retained most of the concept car's performance upgrades. These included a heavy-duty suspension system, bigger brakes, a limited-slip differential, sportier bumpers, side skirts, and bespoke chrome wheels.
Unfortunately, the convertible's 335-hp supercharged V8 wasn't carried over, but the production Marauder did get a 4.6-liter (281-ci) DOHC four-valve version of the Modular V8. Rated at 302 hp, it was the same engine that powered the Mustang Mach 1, and it was enough to propel the sedan to 60 mph (97 kph) from a standstill in 6.9 seconds.
Even if it didn't look much different from the standard Crown Vic or Grand Marquis, the Marauder was a sleeper that felt like a muscle car, particularly in the higher rev range.
2005–2008 Chrysler 300C SRT8
Apart from the standard models, the 300 range included a high-performance version called SRT8. It was powered by a 425-hp, 6.1-liter HEMI and received some unique interior touches, but on the outside, it looked like the regular 300C. The only upgrades that distinguished it from the standard version were slightly different bumpers and a small SRT8 badge located on the trunk lid.
While it looked like a heavy and underpowered American luxury sedan, the 300C SRT8 was an exciting sleeper that performed like a European sports car. Its chassis benefitted from German engineering since Chrysler was still under the same corporate umbrella as Mercedes-Benz, and thanks to the powerful HEMI tucked under the hood, it could accelerate from 0 to 60 mph (97 kph) in 4.9 seconds.
2005–07 Cadillac CTS-V
Under the hood, the CTS-V hid a 5.7-liter LS6 V8 capable of 400 hp, which it shared with the C5 Chevrolet Corvette Z06. That unit was replaced in 2006 with the 6.0-liter L2, but the horsepower rating remained the same.
Apart from the powerful engine that enabled a 0 to 60 mph (97 kph) time of 4.5 seconds, the CTS-V was equipped with various high-performance upgrades. These included a Brembo braking system with 14-inch rotors hugged by four-piston calipers on both axles and a revamped suspension system with higher spring rates and stiffer anti-roll bars.
When it came to exterior upgrades, the CTS-V was easier to distinguish from its standard sibling thanks to wider wheel arches and more aggressive bumpers. Nevertheless, its looks didn't scream high performance. If you saw one in a parking lot, you'd find it hard to believe it was one of the fastest sedans that money could buy.