In October 2019, Indian Motorcycle introduced its most powerful production engine, the PowerPlus 108. It’s a liquid-cooled V-twin that delivers 122 horsepower and 128 lb-ft of torque. It first appeared in the Indian Challenger in 2020 and was a step in a different direction from the brand’s established air-cooled Thunderstroke motors. The PowerPlus 108 is also Indian’s largest engine with a displacement of 1,768cc (108 cubic inches), built to take on Harley-Davidson’s big twin lineup.

Unlike previous Indian engines, the PowerPlus was designed specifically for performance touring. It features modernized technology like ride modes and a six-speed transmission. Overhead camshafts with four valves per cylinder make it smoother and more responsive than older pushrod motors. The engine is used across Indian’s Challenger, Pursuit, and select cruiser models like the Indian Sport Chief. For those asking which Indian engine tops the charts, the manufacturer would tell you this is it. The PowerPlus 108 leads on both paper and the pavement.

The PowerPlus 108 marks a clear departure from Indian’s nostalgic image. By adopting a liquid-cooled platform, Indian improved thermal efficiency, reduced heat at low speeds, and enabled higher compression and rev limits. The end result? A more aggressive, throttle-hungry motor that’s still reliable enough for long-haul touring. This engine offers more than power to riders — it’s engineered for usable torque across the rev range. Peak torque hits at 3,800 rpm and pulls hard throughout the midrange.

Internally, it borrows from the defunct Victory Motorcycle’s Freedom V-twin and Indian Scout architecture, with a modernized SOHC layout. Riders benefit from smoother gear changes, responsive throttle control, and optional traction control systems depending on the model. For Indian, this engine was a declaration — the brand could deliver muscle cruiser power while keeping up with modern emissions and comfort expectations. It transformed the company from a retro revival brand to a serious performance player in the heavyweight V-twin market.

The PowerPlus 108 was built to be in direct competition with Harley-Davidson, especially its Milwaukee-Eight 114 and 117 engines. Compared to the Milwaukee-Eight 114, Indian’s V-twin produces about 20 more horsepower and similar torque, giving it a clear edge in raw acceleration and top-end power. While Harley’s 117 engines can match torque figures, they fall short in the peak horsepower department unless upgraded with Screamin’ Eagle performance kits.

Another advantage is cooling. The liquid-cooled PowerPlus offers consistent performance in hot climates or stop-and-go traffic, where air-cooled Harley engines can feel sluggish or overly warm. That by itself makes a difference for urban riders or long-distance tourers. Ultimately, the PowerPlus 108 gives Indian a foothold in the high-performance bagger segment. It lets Indian compete in both heritage and style, in addition to specs, rider experience, and engineering. For anyone choosing between the two brands, this engine is one of Indian’s strongest selling points.