When Chevrolet revealed the 2025 Corvette ZR1 would generate more than 1,000 horsepower, I was (like all of you out there) stunned by the outrageous number. In subsequent months, I was just as impressed by what a huge jump in output that was compared to the C7 ZR1. Then I started thinking about how much more powerful the ZR1 has grown over the past several decades. Here’s a breakdown
These extremely rare Corvettes (Chevy only built 53 with the ZR1 package across all three model years) had the LT1 350 with no bump in output, which was 370 horsepower in 1970, 330 on lower compression the following year and, after the switch from gross to net ratings, 255 in 1972. However, much of the performance hardware, such as the transmission, brakes, and suspension, was upgraded from the standard Corvette’s.
C4 (1990-1995)
Base Corvettes were powered by a L98 5.7-liter V8, which generated up to 250 horses and 350 lb-ft, depending on the rear end ratio. The reincarnated ZR-1 (with a hyphen this time around) had the same displacement under its hood, but everything else was upgraded. Lotus designed the LT5 engine and equipped it with quad cams, 32 valves, and a special induction system. Output soared to 375 horsepower and 370 lb-ft of torque, increases of 50 and 5.7 percent, respectively.
By 1992, the Corvette used a new version of the LT1 with 300 horsepower and 340 lb-ft. The following year, the ZR-1’s LT5 received a boost to 405 horsepower (up 35 percent compared to the LT1) and 385 lb-ft (up 13 percent).
C6 (2009-2013)
After skipping the C5, Chevrolet brough backt the ZR1 (once again without a hyphen) for the sixth-generation Vette. Just as before, the ZR1’s engine was the same size as the one in the regular model, but more potent. The 6.2-liter LS9 was fitted with a supercharger that helped it crank out 638 horsepower and 604 lb-ft, giving it 46 percent more horsepower and 41 percent more torque than the LS3 with the available dual-mode exhaust system.
C7 (2019)
The Bow Tie crew waited until the C7’s final model year to go all-out with a new ZR1, creating what it called “the fastest, most powerful production Corvette ever.” The supercharged LT4 6.2-liter small-block in the Z06 already produced 650 horsepower and the same amount of torque, but Chevy pushed even further with the ZR1’s LT5. An Eaton supercharger with a significantly higher capacity, larger 95-millimeter throttle body, and two fuel injectors per cylinder (one for port and one for direct fuel injection) contributed to the super-Vette’s staggering 755 horsepower and 715 lb-ft of torque. These were jumps of 64 and 53 percent, respectively, from the Stingray’s LT1 with the available performance exhaust.
C8 (2025-)
For the latest iteration of the ZR1, Chevrolet could have gone high into the triple digits, pushed out a press release, and called it a day. But it decided to shoot past the 1,000-horsepower mark with the 2025 ZR1. Its LT7 5.5-liter V8 is packed with goodies and goodness: double overhead cams, flat-plane crankshaft and, for the first time, twin turbos.
So how far past 1,000 did Chevy go? The ZR1’s final figures are 1,064 horsepower and 828 lb-ft. That means it’s 40 percent more horsepowered and 15 percent torquier than the previous ZR1, which was already eight cylinderfuls of insanity. How does it measure up against the current Stingray’s LT2? Even when that’s hooked up to the optional performance exhaust, there’s still a gap of 569 horses (nearly 115 percent!) and 358 lb-ft (76 percent) between it and the ZR1’s LT7.