2018 Harley-Davidson Road Glide Special Technical Analysis & Specification Breakdown
Engineered by Harley-Davidson for the touring motorcycle segment, the 2018 Harley-Davidson Road Glide Special pairs a 1745 cc (106.5 cu in) oil & air-cooled v2, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 89 HP (65 kW) at 5,450 rpm while maximum torque reaches 150 Nm (110.6 lb-ft) at 3,250 rpm, transferring power to the rear wheel through a 6-speed gearbox and belt final drive. With a specific output of 51 HP per liter and a 2,200 rpm working window between peak torque (3,250 rpm) and peak power (5,450 rpm), the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.
On the scales, the Road Glide Special measures 388 kg (855 lbs) wet (curb), translating to a power-to-weight ratio of 0.23 HP/kg (4.36 kg per horsepower). Rider ergonomics and chassis geometry center around a 695 mm (27.4 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 1,625 mm (64 in) wheelbase engineered for planted straight-line stability. The 22.71-liter (6 US gal) fuel tank paired with a rated consumption of 5.9 L/100 km provides an estimated theoretical range of roughly 385 km (239 miles) between fill-ups.
Within MotoLibrary's Harley-Davidson archive, this model family spans 9 indexed model years from 2015 to 2023, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
51 HP/L
Power-to-Weight
0.23 HP/kg (4.36 kg/HP)
Power Band Window
3,250–5,450 rpm
Theoretical Range
~385 km (239 mi)
Engine
Displacement1745.0 ccm (106.48 cubic inches)
Engine TypeV2, four-stroke
Engine DetailsMilwaukee-Eight® 107
Power89.0 HP (65.0 kW)) @ 5450 RPM
Torque150.0 Nm (15.3 kgf-m or 110.6 ft.lbs) @ 3250 RPM
Compression10.0:1
Bore x Stroke100.0 x 111.1 mm (3.9 x 4.4 inches)
Fuel SystemInjection. ESPFI
Fuel ControlDouble Overhead Cams/Twin Cam (DOHC)
LubricationDry sump
CoolingOil & air
Transmission
Gearbox6-speed
Final DriveBelt (final drive)
ClutchMulti-plate with diaphragm spring in oil bath
DrivelineChain, 34/46 ratio primary drive
Performance
Fuel Consumption5.90 litres/100 km (16.9 km/l or 39.87 mpg)
Greenhouse Gases136.9 CO2 g/km. (CO2 - Carbon dioxide emission)
ExhaustBlack, 2-1-2 dual exhaust with tapered mufflers
Chassis
Rake26.0°
Trail173 mm (6.8 inches)
Front SuspensionTelescopic fork
Rear SuspensionTwin shocks
Wheelbase1625 mm (64.0 inches)
Ground Clearance140 mm (5.5 inches)
Wheels & Brakes
Front Tyre130/60-B19
Rear Tyre180/55-B18
Front BrakesDouble disc. ABS. 4-piston
Rear BrakesSingle disc. ABS. 4-piston
WheelsEnforcer Cast Aluminum
Dimensions & Weight
Dry Weight372.0 kg (820.1 pounds)
Weight incl.388.0 kg (855.4 pounds)
Power/Weight0.2392 HP/kg
Seat Height695 mm (27.4 inches) If adjustable, lowest setting.
Overall Length2430 mm (95.7 inches)
Fuel Capacity22.71 litres (6.00 US gallons)
Oil Capacity3.80 litres (4.02 US quarts)
Other
StarterElectric
Color OptionsVivid Black, Wicked Red, Bonneville Salt Pearl, Hard Candy Hot Rod Red Flake
InstrumentsFairing-mounted electronic speedometer with odometer; time-of-day clock on CD player/stereo; dual trip meter; low fuel indicator light and mileage countdown feature; low oil pressure indicator light; engine diagnostics readout; LED indicator lights; 6-speed indicator light Tachometer with fuel, voltage, oil pressure and ambient air temperature gauges
LightHigh beam, running lights, front fender light, directional light bar, neutral, low oil pressure, engine diagnostics, turn signals, security system (optional), 6-speed, low fuel warning, cruise control (optional), ABS (optional)
Carrying CapacitySaddle bags
Notes
Small windshield. Cruise control. Alarm. Infotainment.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Torque
Torque is useful for judging real-world pull, especially for touring, commuting and loaded riding.
Seat Height
Check the seat height against your inseam and riding posture before choosing a motorcycle.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
