We all expect high-performance cars to entrance us with its sweet siren song. Whether it’s the manic F1-like wail of an Italian V12 revving to oblivion or the guttural growl of a domestic V8 ripping through the gears, there’s no sweeter sound to car enthusiasts’ ears.

But what about those rare automotive outliers that sport all the right performance credentials yet fail to spur goosebumps with their uninspired sound?

To our ears, here are five of the most disappointing-sounding performance cars around:

1. BMW i8

The BMW i8 is an innovative plug-in hybrid sports car that looks like an impossibly cool flying car from the year 2125, but it sounds like a supped-up racing lawnmower from the year 2020. In a questionable move, BMW chose to “enhance” the sound of the i8’s 3-cylinder hybrid powertrain with a speaker mounted in the rear bumper. We’d imagine that most i8 owners sheepishly make their exit from Cars and Coffee meets in full-electric mode.

2. Dodge Viper (first-generation)

To relegate the iconic Dodge Viper to any “worst of” lists is borderline sacrilegious in the eyes of most car guys and gals, but the first-generation Viper RT/10 rightfully earned its spot here. The O.G. Viper was heart-stoppingly gorgeous but it sounded like a mail truck with straight pipes fabricated by a drunk high-school shop student. To make matters worse, the side pipes channeled all this V10 flatulence directly to the ears of the unlucky occupants. Thankfully, subsequent Vipers sound much better than the first-gen model, though they’ll never sound quite as wicked as such competitors as the Corvette.

3. Ford GT (second-generation)

The first-generation Ford GT (available from 2005 to 2006) was a modern road-going interpretation of the legendary Ford GT40 race car from the 60s. When Ford announced that the successor to the first-gen GT supercar would take things in a different direction with a twin-turbocharged V6 engine paired to a 7-speed dual-clutch transmission, fans were hesitant to welcome it with open arms. While the second-gen Ford GT doesn’t disappoint in terms of world-class performance and a visceral race car-like driving experience, its harsh V6 engine is a letdown when it comes to aural excitement. The latest GT sounds loud, uncouth, and uninspiring when compared to the epic supercharged V8 roar of its predecessor.

4. Mercedes-Benz SLK230 Kompressor

Competing with the likes of the BMW Z3 and Porsche Boxster, the Mercedes-Benz SLK230 Kompressor was a chic, luxurious and fun-to-drive retractable hardtop sports car with a lot to offer. Unfortunately, what it didn’t offer was a savory combustion ballad—the SLK230 sounded more like an old tractor than a contemporary roadster. Mercifully, Mercedes rectified the agricultural exhaust note by shoehorning a sweet-sounding 3.2-liter V6 into the SLK in 2001.

5. Porsche 718 Boxster/Cayman

When Porsche replaced the glorious flat-six engine with a turbocharged flat-four in the Boxster and Cayman sports cars for 2017, the automotive press collectively facepalmed for fear that its brilliant engine and exhaust music would hit some sour notes. Tragically, they were right—the 718 Boxster and Cayman sound part Subaru WRX, part VW Beetle, but all-tepid compared to the mellifluous flat-six engine in the former models. Porsche redeemed itself in 2020 by offering a GTS trim for the Boxster and Cayman sporting a magnificent 4.0-liter flat-six replete with a haunting howl.