Watch any car chase movie from the '70s and '80s, and you will likely see the protagonists running rings around the cops. You know the ones, where the police have underpowered cruisers that normally end up in a pile of scrap metal on the highway, or occasionally floating in a duck pond. But while Hollywood loves to present the police as a bunch of also-rans who are comically slow in car chases, the reality is a little different.Police Package vehicles are secret upgrades that are only available to law enforcement, including beefed-up brakes, more power, and other performance goodies, often giving the cops the upper hand. But in the '80s, Chevy decided to give non-badge-wielding folks a level playing field with a model that was based on a cop car. This four-door muscle car was an instant classic. The Impala SS Is A Sleeper Version Of A Police Car For Gearheads via Bring A TrailerThe muscle car scene wasn't showing much sign of revival in the early '90s. Japanese and German imports, not to mention the Malaise era, the oil crisis, and emissions regs, had all meant that a big rorty American V8 four-door wasn't on the top of everyone's shopping list.But out of this era came the Impala SS, a murdered-out prowler as moody as a liquor bottle in a paper bag, that became an instant classic. But behind this spit and sawdust working-class hero was an unlikely pedigree: the Impala SS was the civilian version of a hardworking cop car. But you wouldn't believe it when you look at it, which, uniquely, also makes it one of America's finest sleeper cars. The Impala SS Got Items The Public Weren't Supposed To See Mecum Auctions The Impala SS came about out of desperation. The Chevy Caprice that launched in '91 wasn't selling well; it looked futuristic enough, but its sheer size was accentuated by the drooping rear wheel arch, and the overall appearance was bloated and cumbersome. A year after the Caprice's launch, Chevy head honcho Jim Perkins tasked Jon Moss of GM’s Special Vehicle group with broadening the Caprice's appeal (beyond retirees), and there seemed to be a simple solution. Moss and his skunkworks team took a black Caprice with the 9C1 Police Package and screwed on 17-inch five-spoke wheels.The police package had the new Gen II LT1 engine, with 5.7 liters, as well as a dual exhaust, four-wheel disc brakes, and beefed-up suspension. Simple cosmetic changes, such as opening the rear arch, an integrated rear lip spoiler, a BMW-esque “Hofmeister kink,” and a de-chromed grille and taillight, transformed the look of the Caprice. The final audacious move was to borrow the hallowed "Impala SS" name and stick it on the back. The Cops No Longer Had An Advantage Mecum AuctionsWe're not suggesting for a second that bad guys bought the Impala SS, but if you were someone who had "ditching the cops" on your wish list when buying a new car, then you could do a lot worse. When the SS launched in '94, it didn't just look mean; it had the chops to back up its sinister appearance.The LT1 wasn't exactly the same as the 300-horsepower unit found in the Corvette, but with 260 horsepower, it wasn't far off. Obvious differences were the milder cam to make it a bit more suited to a big four-door, as well as cast iron cylinder heads instead of aluminum. The motor managed 330 lb-ft of torque, channeled through a 4L60-E four-speed automatic transmission (with 3.08:1 gearsets, just like police Caprices) with a column shifter. The transmission was nearly identical to the police package version, calibrated through the programmable control module (PCM) to endow the SS with robust shifting under heavy throttle and full-throttle overdrive upshift. The Impala SS Handled And Accelerated Like A Cop Car via Bring A Trailer The Impala SS, which was built on the GM B-body platform, also borrowed the heavy-duty frame from the police package, with unique springs and shocks made by de Carbon. Brakes were also nabbed from the police package, with 12-inch rotors and single-piston calipers. The SS featured a high-capacity cooling system and transmission cooler. The Impala SS could hit 60 mph in 6.5 seconds and cover the quarter mile in 15 seconds at 92 mph, topping out at around 145 mph. Even the instrument cluster was the same as police models. The Impala SS Was Ahead Of Its Time Mecum AuctionsBy using police-issue parts, Chevy had almost accidently created one of the new wave of muscle cars — it was just that the Impala SS was ten years too early. By swapping out the stock Chevy 180-horse 5.7-liter small-block V8 for the hotter LT1, Chevy had done the same simple hot rod job that muscle car manufacturers had done in the '60s, with great success. The performance figures of the '90s Impala Super Sport were only a shade off legit '60s legends such as the 1965 Chevrolet Chevelle Malibu SS and 1969 Ford Mustang Boss 302. The Impala Was A Lone Wolf In The World Of Four-Door Muscle Cars via Bring A Trailer When it came to '90s muscle cars, the Impala SS didn't have much competition, especially in the four-door variety, with models such as the 1989 Ford Taurus SHO only managing around 220 horsepower from a V6, with the quarter being dispatched in 15.1 seconds. In short, the Impala SS was a proper muscle car, but it predated the second golden era of the genre, which was marked by models such as the sixth-gen (LX) Dodge Charger, which arrived in 2006. But that didn't stop the Impala SS from quickly becoming a cult legend, especially in the hip hop community, with famous owners such as Killer Mike from Run the Jewels. Buying An Impala SS Today via Bring A TrailerThe original price of the Impala SS was around $22,500, but these cars haven't lost much of that value today. Expect to pay $17,400 for a '94 to '96 model today, says Hagerty Valuation Tools. While it's impressive that this '90s V8 has kept its value, considering its iconic status, that's not a lot of cash to hand over. The low prices are down to the SS's popularity when new. The Impala SS Sold Well For Chevy — But Was Canceled Too Quickly via Bring A TrailerChevy sold 6,300 1994 SS models (only sold in black with a gray interior), says Hagerty, but the secret of the police-spec Impala was well and truly out in 1995, with more than 21,000 sold. In 1996, Chevy sold an incredible 42,000 Impala SSs, helped in part by a redesigned instrument panel with tachometer, with the shifter being relocated from column to the floor. The whole B-body line was discontinued after 1996, and the Impala returned for the year 2000 as a front-wheel drive V-6 sedan, with the ninth-gen cars from 2006 also getting six-cylinder mills. That's a shame really, as the Impala could have been a worthy adversary to the likes of the reborn Dodge Charger, and a much-loved V8 model in the revived muscle car scene of the 2000s.Sources: Hagerty.com; Hemmings.com