PowerPlus 108 vs Milwaukee-Eight VVT 117: The Liquid-Cooled Bagger Engines
Updated: Sep 28
Quick answer: On torque Harley wins narrowly and on horsepower Indian wins clearly. The Milwaukee-Eight VVT 117 makes 131 ft-lb at 3,250 rpm and 106 hp. Indian's PowerPlus makes 128 ft-lbs at 3,800 rpm and 122 hp. Harley gets there with 117 cubic inches against Indian's 108, and 550 rpm lower down. What settles the purchase is not the three ft-lb, it is that the PowerPlus baggers start at $27,999 while the Harleys carrying the VVT 117 start at $32,999.
Disclosure: MotoGearRater and Legendary USA have the same owner. Links to legendaryusa.com in this article go to our owner’s store, and are marked as sponsored. How we make money
MotoGearRater does not run dynos and holds no independent test data. Every number below is the manufacturer's own, and where one of them declines to publish something we say so rather than borrowing a figure from elsewhere. Gear is the one area where we hold a view of our own, and a January ride on a liquid-cooled bagger is a specific problem, which is why Legendary USA is the reference point in the section further down. These engines throw less heat at the rider than an air cooled twin does, and that is a gear question as much as an engineering one.
All prices are base MSRP and exclude freight, destination and dealer charges.
Which engine goes in which bike, because this is easy to get wrong
The Milwaukee-Eight VVT 117 is not the engine in every Harley bagger. It appears on the Street Glide Limited, the Road Glide Limited and Harley's two three-wheelers. The base Street Glide and Road Glide use the non-VVT Milwaukee-Eight 117, which Harley rates at 130 ft-lbs at 3,250 rpm. If you have read a comparison that treats those two as the same engine, it was wrong.
On Indian's side the PowerPlus 108 is a single engine across three bikes, the Chieftain PowerPlus Dark Horse and the Challenger Dark Horse at $27,999 each, and the Pursuit Dark Horse at $32,499. Indian's specs pages list it identically on all three: liquid-cooled PowerPlus, 108 cubic inches, 1,768cc, 122 hp, 128 ft-lbs at 3,800 rpm.
Cooling is worth being precise about, because it is where the marketing gets loose. Harley's own 2026 Road Glide page refers to the liquid-cooled cylinder heads in its Milwaukee-Eight engine, and both the Street Glide and Road Glide pages describe the motor as a liquid-cooled Milwaukee-Eight 117. Indian's spec page reads simply Liquid-Cooled PowerPlus. Those are two different depths of the same idea, and neither company publishes a figure that would let you quantify the difference. Anyone who tells you exactly how much cooler one runs than the other has made it up.
The numbers, side by side
Displacement. Milwaukee-Eight VVT 117, 117 cubic inches. PowerPlus, 108 cubic inches, 1,768cc. Harley is nine cubic inches larger.
Torque. VVT 117, 131 ft-lb at 3,250 rpm on Harley's J1349 method. PowerPlus, 128 ft-lbs at 3,800 rpm. Indian does not describe its testing method in the same terms Harley does, so a three ft-lb gap between two differently measured numbers is not a result, it is a coincidence of rounding.
Horsepower. Indian publishes 122 hp for the PowerPlus. Harley lists 106 hp for the VVT 117 in the Street Glide Limited and the Road Glide Limited. That is a 16 hp gap in Indian's favour and it is a real comparison rather than a blank, because both figures come from the makers themselves. The two companies do not describe their testing the same way, so read the 16 as directional rather than as a dyno result.
Weight, running order. Street Glide Limited 893 lb. Road Glide Limited 919 lb. Chieftain PowerPlus Dark Horse 842 lb. Challenger Dark Horse 855 lb. On like for like running order figures the Indians are the lighter bikes by 38 to 77 lb depending on which pair you line up.
Fuel. The PowerPlus baggers carry 6.0 gallons. The Harley Limiteds carry 6 gallons. That one is a draw.
Price. Street Glide Limited and Road Glide Limited both $32,999. Chieftain PowerPlus Dark Horse and Challenger Dark Horse both $27,999. That is a $5,000 gap in Indian's favour for a comparable amount of motorcycle.
The cold weather gear a liquid-cooled bagger needs
There is a real ergonomic consequence to liquid cooling that nobody puts on a spec sheet. An air cooled big twin dumps heat onto the rider's legs and, in traffic, onto their hands. A motor that manages its own temperature more effectively gives you less of that back. In July that is the whole point. In January it means you are on your own.
Fleece-Lined Deerskin Gloves, $111. This is the specific answer to the problem above. Deerskin outer for the feel at the lever, fleece inside for the two hours before the sun gets up, and short wrist so it lives under a jacket cuff rather than fighting it. No armour and no certification, which is the accurate description of it.
Aramid Touchscreen Deerskin Gloves, $123. Both of these bikes are operated through a screen, Skyline OS on the Harley and Ride Command on the Indian, and a glove you have to peel off at every fuel stop to change a setting is a glove that ends up in a saddlebag. The aramid here is a lining material, not a rating, and we are not claiming an abrasion figure for it.
BECK 732 Northeaster Flying Togs Black Horsehide Jacket, from $815. A full fairing takes the blast off your chest and leaves your shoulders and upper arms in the air that came over the top of it. Horsehide is the densest of the common hides and it is the layer that stops January being the reason you did not ride. BECK is Legendary's own house line rather than a label carried in from elsewhere.
Nothing above is CE rated and nothing above is armoured. That statement appears in every gear section here because it is true and because riders deserve to know it before they spend. Alpinestars builds armoured cold weather touring kit and is the straightforward comparison if protection rather than material is the priority. The case for the list above is American leather, the right cut for an upright bagger, and prices that stand up next to a dealership accessory counter.
So which one is stronger
On published torque, the Harley, by three ft-lb, delivered 550 rpm lower in the rev range, from nine more cubic inches. That last part matters more than the headline. A larger engine making slightly more torque earlier is a different character from a smaller one making slightly less a bit later, and the PowerPlus is the more willing of the two to be revved because that is where its numbers live.
On published horsepower Indian is ahead, 122 against the 106 Harley lists for the VVT 117. That is the clearest single spec win in this comparison, and it runs the opposite way to the torque figure, which is why neither number settles the argument on its own.
On value, Indian, clearly. $27,999 buys the PowerPlus in a Chieftain or a Challenger. The cheapest Harley carrying the VVT 117 is $32,999. Five thousand dollars is not a trim level, it is a different budget conversation.
One caution about anything you read ranking these two commercially. Neither Harley-Davidson nor Polaris publishes model level unit sales, so nobody can tell you which bagger engine is in more driveways. Any claim of that kind is inference dressed as data.
Which one to buy
Buy the PowerPlus bike if the engine is genuinely what you are choosing. It gives you the bigger published horsepower number, 122 against 106, it is the lighter package in running order, and it saves you $5,000 against the cheapest Harley with the VVT motor. For a rider who wants the modern liquid-cooled bagger engine and does not need a Harley badge, the Challenger Dark Horse at $27,999 is the strongest case in this comparison.
Buy the Street Glide Limited or Road Glide Limited if the rest of the motorcycle is what you want and the engine is simply the thing that comes with it. 131 ft-lb at 3,250 rpm is the highest published torque figure of any bike named in this post, it arrives lower than Indian's does, and Harley's dealer and parts network is the deepest in the country. You are paying $32,999 for a package, not for three ft-lb, and it is reasonable to want the package.
Related reading on MotoGearRater: the Milwaukee-Eight engine guide, PowerPlus vs Thunderstroke, and Indian Challenger vs Harley Road Glide.
