Harley-Davidson STREET GLIDE – FLHX (2006–Present) Factory Oil & Tire Pressure Data

Quick Specs: Street Glide FLHX
ComponentSpecification
Production Years2006–Present
Engine Oil20W50 HD 360 / SYN3 (3.8 L – 4.7 L)
Tire Size (F/R)130/60B19 61H / 180/65B16 81H
Tire Pressure (F/R)2.5 bar (36 psi) / 2.8 bar (40 psi)
Battery Model66000212
Spark PlugsHD-6R12 / HD-10R12A

Before it became the flagship of the modern bagger movement, the Street Glide (FLHX) began as a personal project by Willie G. Davidson. In 2006, he sought to create a “factory custom” that stripped away the excess of the Electra Glide while maintaining the iconic Batwing fairing. This engineering philosophy birthed the “Slammed” look, forever changing the Grand American Touring landscape by lowering the rear suspension and simplifying the profile.

Engineering Overview

The FLHX chassis is built on the Harley-Davidson Touring frame, which underwent a massive redesign in 2009 to improve stability and heat management. Whether powered by the Twin Cam 88, 96, 103, or the modern Milwaukee-Eight (M8) powerplants, the Street Glide demands rigorous adherence to fluid intervals to protect its high-torque output.

Lubrication System

For optimal performance, MotoSpecsLab recommends 20W50 HD 360 for standard climates or SYN3 Synthetic for high-heat environments. The oil capacity varies between 3.8 L and 4.7 L; always check the dipstick while the bike is on its jiffy stand (for older models) or upright (for certain M8 iterations) as per your specific VIN-year manual. The three-hole oil change (Engine, Primary, Transmission) remains a staple of the FLHX maintenance ritual.

Chassis and Contact Patch

Handling a 800lb+ machine requires precise tire maintenance. The FLHX utilizes a 130/60B19 front and a 180/65B16 rear. To prevent cupping and ensure high-speed stability, pressures must be maintained at 36 psi (Front) and 40 psi (Rear). Given the weight of the Batwing fairing, front tire wear is often accelerated under heavy braking.

Electrical and Ignition

The modern Street Glide is a rolling computer, featuring the Boom! Box Infotainment system. This puts a significant load on the charging system. The 66000212 battery is the standard high-CCA (Cold Cranking Amps) unit required to turn over the large-displacement V-Twin. For ignition, the HD-6R12 or HD-10R12A plugs provide the necessary heat range to prevent pre-detonation in air-cooled cylinders.

Maintenance Pro-Tips

  • Drive Belt: Inspect tension every 5,000 miles. A loose belt on a Street Glide can lead to premature pulley wear.
  • Air Suspension: For pre-2017 models, check the air pressure in the rear shocks regularly. 2017+ models utilize hand-adjustable emulsion shocks.
  • Brake Fluids: The FLHX uses DOT 4 fluid. It is hygroscopic and should be flushed every 2 years to prevent ABS module failure.

The Harley-Davidson Street Glide remains a benchmark of American engineering. By following these technical specifications, owners ensure the longevity and resale value of this iconic machine.

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