The 2025 Duke 390 roars to life with a 399 cc LC4c single-cylinder engine delivering 44 HP and 28.8 lb-ft torque, rockets to 104 mph GPS-verified top speed, and carries a $5,899 base MSRP in the US.
On paper, the Duke 390 outguns the Kawasaki Ninja 300’s 39 HP and Yamaha R3’s 42 HP. In practice, testers clock 0–60 mph in around 5.5 seconds, making it one of the quickest sub-400 cc bikes. Its bi-directional quickshifter and torque-rich midrange punch give it a decisive edge in traffic and canyon runs alike.
Top Speed Reality Check
Official vs. Indicated
- Manufacturer Claim: 104–105 mph GPS-verified top speed under ideal conditions.
- Speedo Reality: Riders report 110–115 mph indicated, translating to ~104 mph actual once calibrated.
“It holds 100 mph all day stable—no wallow even when you tuck in.”—SR Motoworld test rider, July 2025
Real-World 2025 MSRP Breakdown
- Base MSRP: $5,899
- Freight & PDI: ~$575
- Destination & Doc Fees: ~$300
- Total Before Tax: ~$6,774
Competitive Context
| Model | MSRP (USD) | Top Speed | Power |
|---|---|---|---|
| 2025 Duke 390 | $5,899 | 104 mph | 44 HP |
| Kawasaki Ninja 300 | $6,199 | 112 mph | 39 HP |
| Yamaha R3 | $5,199 | 110 mph | 42 HP |
The Duke undercuts competitors by hundreds and still packs a punch. It’s 399 cc single-cylinder LC4c mill produces 44 HP at 8,500 rpm and 28.8 lb-ft torque at 7,000 rpm, paired with a slick 6-speed gearbox, slipper clutch, and quickshifter+.
As one Rider sums it up: “You get near-superbike power in a U-turn-friendly package”—and all without needing a second mortgage.
Real-World Mileage
In mixed city riding with stop-and-go traffic, many see 20–23 km/L (47–54 mpg), dropping to 17–18 km/L under spirited throttle. On steady highways at 100 km/h, you’ll average 27 km/L (63 mpg), but throttle back to 80 km/h in sixth gear, and some report 33 km/L (78 mpg).
One Rider logged a 600 km test ride and summarized: “At 50 km/h you max 40 km/L. Cruising at 60 km/h, it’s 38 km/L. At 80 km/h you hit 33 km/L, and at 100 km/h around 27 km/L.
Between 100–120 km/h, it drops to 22–25 km/L.” These real-world figures translate to 57–65 mpg for daily commutes, keeping monthly fuel bills under $60 for most riders.
Ownership Realities
Daily-ridden Dukes prove durable, even when flogged. One industrious Rider logs 150 miles a day, redlining most of it, and reports zero failures over 3,000 miles of high-mileage abuse! Another notes the BS6–tuned engine runs smoothly after 23,000 km with nothing more than routine oil top-ups and brake pad changes, leading him to declare, “I’ll never sell it.” These owner testimonies suggest that, with timely oil changes and valve checks, the Duke’s LC4c engine will hum on reliably well past 20,000 miles.
The Good, the Bad, and the “No Windshield”
Pros:
- Lightweight, torquey midrange—corner carving is addicting.
- Quickshifter+ makes every upshift satisfying.
- ABS and traction control work silently; confidence-inspiring.
Cons:
- No windshield: highway blasts toss bugs in your teeth.
- High service intervals (7,600 km) mean dealer visits eat into weekend fun.
- Firm seat—hour-long rides leave the tailbone begging for mercy.
