The 392 HEMI engine in a Dodge Challenger R/T Scat Pack.If you've wondered why modern engines are described in liters — even in America — the correct answer is quite boring. Automakers build engines for worldwide markets, and liters are the common units of measurement for engine displacement. Over time, even the U.S. auto industry has steadily aligned itself with metric standards, which makes "3.0" or "6.2" easier to market globally than "183" or "376."Despite the shift from imperial to metric over 40 years ago, cubic inches never truly died. They just moved to places where numbers are no longer solely used for measurement but also marketing — crate engines, heritage badges and motorcycles still feature the same "freedom units" of decades past.The most prominent modern automaker that still treats displacement like a nameplate is Stellantis. Mopar's 6.4-liter crate Hemi is sold as a "392" and was fitted in Dodge's Charger and Challenger Scat Pack for years. In case that isn't enough, Dodge's Direct Connection factory-backed performance program sells the Hellephant A30 Supercharged Hemi 426 crate engine that leans into the 426 Hemi moniker, which became iconic during the '60s and '70s. Freedom units are still going strong in the American muscle and motorcycle scenesA white 2027 Chevrolet Corvette Grand Sport an a Black 2027 Corvette Grand Sport XFord plays the same game in its performance catalog. Ford Performance's crate engine listings prominently use cubic inches. 347 and 460 show up as headline displacements in the specs, because that's how the hot rod world shops. Meanwhile, Chevrolet doesn't just keep cubes alive; it organizes its entire crate engine universe around them. Chevy's performance catalog still sells big-block offerings such as the 621-horsepower 572 crate with the displacement baked into the product identity. Even with its production cars, Chevrolet still sneaks cubic inches into the conversation when it suits the story. General Motors' press release for the newly announced Corvette Grand Sport X refers to its 6.7-liter V8 as a 409. The "freedom unit" displacement is instantly legible to anyone who has ever spent time around American performance lore.It's not just cars. "Freedom units" also remained delightfully normal in motorcycles. Indian Motorcycle describes the Scout Sixty as having a "60 cu-in liquid-cooled engine" right there in the spec sheet. Similarly, Harley-Davidson lists their iconic Fat Boy cruiser with only its cubic inch displacement ("117 cu in.")Liters may have won the global spec war, but cubic inches still thrive where engines are sold with a side of nostalgia — where displacements aren't just numbers but also branding. And in a country that prides itself in the excessive size of its motors such as America, "freedom units" aren't going away anywhere soon. Want more like this? Join the Jalopnik newsletter to get the latest auto news sent straight to your inbox, and add us as a preferred search source on Google.