5 Generations of Chevy Impala SS Ranked, With 425 hp at the Top
A new ranking of the five Chevy Impala SS generations puts the 1960s cars on top at up to 425 horsepower. Later models from the 1990s and 2000s made 240 to 303 hp. The figures come with a catch: early cars used gross ratings.
The five generations of the Chevy Impala SS, ranked by peak horsepower, put the 1960s cars first: the retail Super Sport models from that decade produced up to 425 hp. The later SS generations from the 1990s and 2000s made between 240 and 303 hp, according to a new ranking from Jalopnik's auto desk.
The Impala SS (Super Sport) dates back to 1961, two years after Chevrolet launched the Impala as its own model. Even by 21st-century standards, the numbers are high.
Why the numbers need a footnote
The 1960s figures were gross horsepower ratings. Those generally did not account for intake, exhaust and accessory loads.
By the 1972 model year, Detroit had switched to net horsepower, which better reflects real-world engine setups. The change followed tighter emissions rules and insurers wary of high-powered cars.
There is no standard way to convert between the two methods, because gross ratings varied from one manufacturer to the next. Both still measure power at the crankshaft, not the wheels.
The ranking uses the highest advertised rating for regular-production SS models, gross or net. Special race versions and modified cars are excluded.
1961-1964: up to 425 hp
The SS badge arrived with the third-generation Impala in 1961. The second generation, which had no Super Sport option, filled the two-year gap.
The 1961 SS offered 348-cubic-inch V8s rated at 305, 340 or 350 hp, plus a 409-cubic-inch V8 rated at 360 hp. In 1962, the 409 could be fitted with dual four-barrel carburetors, lifting output to 409 hp.
Solid lifters, dual exhausts and an 11:1 compression ratio pushed the 409 to 425 gross hp for 1963. The 1964 SS kept the same engine.
A 1963 Z11 drag-racing Impala with a 430-horsepower 427-cubic-inch V8 does not count. It was not an SS and not regular production, and only 57 were built.
1965-1969: up to 425 hp again
Peak power stayed at 425 hp for the next generation, but Chevy got there differently. The 1965 Impala had a sleeker body and a perimeter frame, replacing the X-type architecture of the old car.
It became the best-selling single model of all time, with 1,046,514 units sold. Roughly 23% were SS variants.
The top engine in the non-SS 1965 Impala was the 409-cubic-inch Turbo-Fire V8 at 400 hp. SS buyers could also order the L78, a 396-cubic-inch V8 rated at 425 gross hp.
A year later the L72 427-cubic-inch V8 joined the list, also rated up to 425 hp. It had a forged crankshaft and pistons, solid lifters and dual exhausts. The SS 427 continued into 1967 and 1968.
Take the quizWhat Kind of Holiday Spender Are You? Take the Black Friday QuizStart →- 1Mavericks Surfers Race to California for Waves Near 50 Feet
- 2Rugby League World Cup Final 2026: Kick-Off Times and How to Watch Kangaroos v New Zealand
- 3Canadiens Expected to Re-Sign Josh Anderson at Lower Salary, Insider Says
- 4NYC Medical Examiner Has Not Determined Cause of Death of Beau Rose Jessup
- 5Fiber Supplement Could Help Millions With IBS, Australian Study
Lifestyle7 Signs Your Social Battery Is Running Low (and Why You Keep Cancelling Plans)
Lifestyle · Food & HealthThanksgiving Food Safety: How Long Leftovers Last and the Safe Turkey Temperature
Lifestyle7 Quiet Habits of Emotionally Intelligent People, According to Psychologists
LifestylePeople Who Don’t Like Celebrating Their Birthday Often Share These 7 Traits
