Why Newer Harley-Davidsons Have A Different 'Potato' Engine Sound

The allure of owning and riding a Harley-Davidson motorcycle is connected to the company's rich history, popularity, and legacy. But for those who have ridden Harleys for years, nothing quite beats the "potato" sound of the bikes' engines. But as those same riders likely know, that classic Harley sound has changed on the company's newer models. The reason for that has to do with the engine itself.

Many modern Harley‑Davidsons, like the 2026 Road Glide, utilize the Milwaukee‑Eight engine, a 2017 step up from the company's famous Big Twin design. That engine gave Harleys their classic, unique sound. The Milwaukee-Eight relies on a single chain-driven camshaft, lighter valve train components, and internal parts that reduce mechanical noise, as well as vibration. So riders still get the same power and torque, but a quieter ride when compared to some Harley models from years prior. That familiar potato sound has evolved into a smoother and far less aggressive tone, depending on the bike's exhaust setup. The rumble is still there, but the sound is different.

Evolving government regulations have changed the sound of Harleys as well. For example, the United States noise emission standards require that a bike's total sound doesn't exceed specific decibel limits at the time of sale. The same is true in Europe, as Harleys must comply with strict noise and emissions regulations before a sale is approved. As a result, the company had to alter its engines and systems, which impacted the sound of the bikes themselves.

Older Harley-Davidson models with the classic "potato" engine sound, which Harley tried to trademark in 1994, aren't federally required to meet noise emission standards in the US. However, Harley owners should be aware of state and local noise ordinances, which determine how loud a motorcycle is allowed to be on public roads. Some cities even require aftermarket mufflers to meet specific decibel levels. Harley owners riding loud bikes should check with their local government for more information, or risk potentially getting a ticket.

Despite noise ordinances, many Harley-Davidson owners modify their bikes in an effort to get more of that old-school potato sound. This is accomplished through aftermarket systems, which open up the exhaust to create a louder and more aggressive sound. By making this change, riders are actually improving their overall power to some degree, though the main goal is to achieve that loud rumble.

However, such modifications could actually be illegal, depending on state regulations governing where the rider lives. Also, while using aftermarket mods on a Harley-Davidson doesn't automatically void the warranty, if damage occurs to the motorcycle or components as a result, then all bets are off. At that point, Harley may say no to warranty repairs, which means any costs from a failed aftermarket modification would have to be paid by the owner out-of-pocket.