| Component | Specification |
|---|---|
| Engine | Milwaukee-Eight 114 V-Twin (1,868cc) |
| Oil Type | H-D 360 20W50 / SYN3 (4.7 L) |
| Spark Plugs | Harley-Davidson 6R10 |
| Tire Size | F: 130/60B19 | R: 180/55B18 |
| Battery | Part #66000208 |
The 2019 Harley-Davidson Street Glide Special (FLHXS) represents a pivotal engineering milestone in the Touring family. While many enthusiasts focus on the aesthetics, the 2019 model was the first year the Milwaukee-Eight 114 engine became the standard powertrain for the Special trim, transitioning from the 107. This engine features a unique precision cooling system that targets the cylinder heads, combined with a dual-spark plug design per cylinder to optimize combustion efficiency and thermal management under heavy touring loads.
The Milwaukee-Eight 114: Engineering Analysis
The 114 cubic inch (1,868cc) power plant delivers a massive 163 Nm of torque at 3,000 RPM. From a technical standpoint, the four-valve-per-cylinder head design allows for a 50% increase in intake and exhaust flow capacity compared to previous generations. For the technician, this means maintaining the valve train is less frequent, but ensuring the oiling system is pristine is critical due to the high-volume oil pump required to cool the exhaust valves.
Maintenance Specifications & Fluids
Adhering to strict fluid intervals is paramount for the longevity of the M8 engine. MotoSpecsLab recommends the following:
- Engine Oil: The system requires 4.7 Liters. Use H-D 360 20W50 Mineral for break-in or Screamin’ Eagle SYN3 20W50 Synthetic for high-temperature protection.
- Ignition: Utilize Harley-Davidson 6R10 plugs. Ensure the gap is set to factory specifications to prevent misfires in the high-compression 10.5:1 chambers.
- Electrical: The 2019 model utilizes the high-output battery (Part #66000208) to support the Boom!™ Box GTS infotainment system.
Chassis & Handling: The Blacked-Out Performance
The FLHXS/19 sits on Talon wheels, which require specific tire profiles to maintain the intended geometry. The front 130/60B19 and rear 180/55B18 setup provides a balance between stability and flickability. Critical Safety Note: Always maintain pressures at 36 psi (Front) and 42 psi (Rear) to prevent uneven cupping, which is common on heavy touring frames when under-inflated.
MotoSpecsLab Verdict
The 2019 Street Glide Special is a masterclass in modern bagger engineering. By integrating the 114 engine as standard, Harley-Davidson elevated the performance ceiling of the FLHXS. For owners, the key to performance retention lies in the 5,000-mile service intervals and the use of high-thermal-stability lubricants.