PowerPlus vs Thunderstroke: Indian's Two Answers to the Same Question

Most cooling arguments are between brands. Indian's is inside one showroom. The company sells a liquid-cooled PowerPlus and an air-cooled Thunderstroke at the same time, to buyers who are often cross-shopping them against each other, and it has not shown any interest in picking a winner.

Two Engines, One Floor

The PowerPlus 108 arrived in 2020 in the Challenger: 1770cc, liquid-cooled, 122 hp and 128 lb-ft. Seat height 26.5 inches, 796 lb wet, $21,999. Indian launched it as a flagship and ran an explicit Challenger Challenge campaign aimed directly at the Harley Road Glide Special, which tells you exactly which buyer it was built for.

The Thunderstroke sits in the Chief, which arrived as an all-new MY2022 platform: steel-tube frame, round headlight, 4-inch round TFT, 26 inch seat, 670 lb in base form, and prices from $14,499 to $20,999 across six variants. Buyers choose between the Thunderstroke 111 at 1811cc and 108 lb-ft, or the 116 at 1890cc and 120 lb-ft. Both are air-cooled.

Set the headline numbers next to each other and the liquid-cooled engine wins on paper: 128 lb-ft against 120 from the largest Thunderstroke, with 122 hp quoted where the air-cooled engines are sold on torque alone. Set the weights next to each other and the picture inverts. The Challenger is 796 lb wet; the base Chief is 670 lb. That gap is most of what the cooling decision actually costs.

What Liquid Cooling Buys, and What It Charges For

A liquid-cooled engine holds a tighter temperature range, which lets a designer run closer tolerances, higher compression and a higher rev ceiling without the metal moving around underneath. That is why the PowerPlus can quote a power figure at all in a category where competitors usually quote only torque.

The bill arrives as parts and mass: radiator, pump, hoses, coolant, fans and the packaging space to put them. Some of the 126 lb between the Challenger and the base Chief is fairing and equipment rather than cooling system, and it would be dishonest to attribute it all to the radiator. But the direction is not in dispute, and neither is the added service surface. More components that can leak is simply what a cooling circuit is.

What Air Cooling Keeps

The Thunderstroke's argument is subtraction. No radiator, no pump, no coolant, no hoses, and finned cylinders that look like what a lot of cruiser buyers came to the category for. It also allows the Chief's 670 lb base weight and its $14,499 entry price, which is a long way under the Challenger.

The constraint is that the engine's temperature is set by airflow, and airflow is set by road speed. At a standstill there is nothing to manage it with, which is why heat complaints in this category are always stop-and-traffic complaints rather than highway complaints. The 111 and 116 make their case at 108 and 120 lb-ft respectively, which is plenty of engine, arriving through an architecture with fewer things in it.

Why Indian Kept Both

The sequence is the tell. The liquid-cooled Challenger launched in 2020 as the flagship. The all-new air-cooled Chief platform arrived two model years later, in MY2022, after the liquid-cooled bike was already on the floor. Indian had every opportunity to make the Chief liquid-cooled and did not.

The Scout complicates any neat theory further, because it is liquid-cooled too, running 1133cc and 100 hp at 8,100 rpm through most of this window before the SpeedPlus 1250 replaced it for MY2025 with 105 hp and 82 lb-ft at 6,300 rpm. So Indian is not an air-cooled company hedging with one radiator. It is a company that picked cooling per platform, based on what each motorcycle was for.

How that played out commercially is not knowable from public data. Harley-Davidson publishes no model-level unit sales, and neither does Polaris for Indian or Honda for the US market. BMW Motorrad is the only one of the four that does. Indian's global volume passed 30,000 for the first and only time in this window in 2021 and was 25,792 in 2024, but those are brand figures. Our 2020 Indian best seller post and 2022 Indian best seller post lay out what can and cannot be established for the Challenger and Chief launch years.

What Owners Report About Heat

The consistent line in Challenger feedback is that the bike runs cooler than the air-cooled alternatives but is not cool. Liquid cooling moves heat away from the cylinders efficiently; it then has to put that heat somewhere, and on a large V-twin that somewhere is often close to the rider's legs. Owners who expected the radiator to eliminate the issue generally report that it reduced it instead. That, and the rest of what comes up in ownership, is in our Indian Challenger owner reports.

That is the finding worth carrying into a showroom: the cooling decision changes the degree of the heat complaint, not whether the complaint exists.

A Note on Layering

Riders who move between these two engines usually end up rethinking their mid-layer before anything else, because a bike that puts heat at your legs in traffic and cold air at your chest at speed is asking for something you can add and remove without stopping. Vests get bought for that job and often turn out to be built for a different one. Legendary USA's piece on the difference between a riding vest and a fashion vest is a fair breakdown of what separates the two before you spend.

What This Means for a Buyer Today

Decide what your riding actually looks like before you decide what the engine should be. If most of your miles are highway, air cooling is being handed the conditions it was designed for and the Chief's 670 lb base weight and $14,499 entry price are real advantages. If a meaningful share of your miles are urban, in traffic, in summer, the PowerPlus is solving a problem you will genuinely have.

Weight is the other honest filter, and it is felt at walking pace rather than in the numbers. 796 lb wet against 670 lb is not a trim difference. Anyone who has to reverse a motorcycle up a sloped driveway should treat that as a separate decision from the engine spec.

Displacement inside the Thunderstroke range is a smaller decision than it looks. The 111 at 108 lb-ft and the 116 at 120 lb-ft are the same architecture with a 12 lb-ft spread. If budget is tight, the base engine is not a compromised version of the motorcycle, and $14,499 to $20,999 across six variants means most of the money is going somewhere other than the cylinders.

Indian selling both, at once, to overlapping buyers is the most useful thing about this comparison. A manufacturer that had a definitive answer would only be selling one.

Cover photo: "Indian Roadmaster - June 2024 - Sarah Stierch" by Missvain, CC BY 4.0, via Wikimedia Commons.