In most cases, I would guess that an engine replacement under warranty would be quite uncommon. I expect that among leadfoot gearheads like us, engine replacements on new cars might be more common. Like [MENTION=750]RICH17[/MENTION] mentioned however, Hyundai seemed pretty quick to replace the motor on my girl's 2011 Elantra. I presented it with what sounded like an exhaust leak, they looked it over and said they were going to replace the engine. Afterwards, the tech gave me some explanation that made absolutely no sense about "direct injection engines creating more carbon deposits on the pistons which create hot spots which leads to premature detonation and engine damage." That goes against everything I know about direct injection and carbon deposits on the pistons.