11. Subaru EJ20 Boxer Engine (Impreza WRX STI)
Subaru’s turbocharged EJ20 boxer engine became legendary during the ’90s, thanks to its unmistakable deep, rumbling tone and rally-bred heritage. Defined by its horizontally opposed cylinders and unequal-length headers, this distinctive powerplant produces an aggressive idle that quickly escalates to a resonant, throaty growl under acceleration. Fans of motorsport will instantly recognize the EJ20’s signature burble, reminiscent of Subaru’s dominance in World Rally Championship events. Its uniquely mechanical and rhythmic soundtrack, coupled with the iconic whistle of the turbocharger, continues to captivate car enthusiasts, cementing the EJ20 as one of the decade’s most beloved engine sounds.