| Specification | Data |
|---|---|
| Production Years | 2009 – Present |
| Engine Oil | 20W50 HD 360 / Screamin’ Eagle Syn3 (3.8 L – 4.2 L) |
| Front Tire | 130/70BW18 M/C 63H (36 psi) |
| Rear Tires | P205/65R15 92T (26 psi) |
| Battery Model | 66010-97D |
| Spark Plugs | H-D 60100010 (2017+) / 6R12 (2009-2016) |
Engineering Legacy: A Return to Three Wheels
The introduction of the FLHTCUTG Tri Glide Ultra in 2009 marked a historic pivot for Harley-Davidson. It was the first factory-produced three-wheeled motorcycle from the Milwaukee manufacturer since the iconic Servi-Car was discontinued in 1973. Unlike aftermarket conversions, the Tri Glide was engineered from the ground up with a chassis specifically designed to handle the unique lateral forces of a non-leaning trike, featuring a longer wheelbase and a reinforced rear axle assembly.
Technical Maintenance & Lubrication
Maintaining the Milwaukee-Eight or Twin Cam powerplants found in the Tri Glide series requires strict adherence to lubrication standards. For the engine, 20W50 Harley-Davidson 360 is the standard mineral choice, though Screamin’ Eagle Syn3 is highly recommended for better thermal stability in the rear cylinders, which often run hotter due to the bodywork’s airflow restrictions. Capacity typically ranges from 3.8 L to 4.2 L depending on filter change and oil cooler drainage.
Chassis and Contact Patch
The Tri Glide’s stability is heavily dependent on precise tire pressure management. The front 18-inch wheel requires 36 psi (2.48 bar) to maintain steering precision and prevent ‘cupping’ under heavy braking. Conversely, the rear automotive-style tires (P205/65R15) operate at a significantly lower 26 psi (1.79 bar) to ensure a compliant ride and maximum traction across the wider contact patch.
Electrical and Ignition Systems
Reliable starting is provided by the 66010-97D battery, which offers the high Cold Cranking Amps (CCA) necessary to turn over the large-displacement V-Twin. For ignition, owners of 2017 and newer models (Milwaukee-Eight) should utilize the H-D 60100010 plugs, while earlier Twin Cam models (2009-2016) utilize the classic 6R12 spark plugs. Proper gapping is essential to prevent hesitation under load.
MotoSpecsLab Editorial Verdict
The FLHTCUTG remains the gold standard for long-haul touring trikes. Its integration of a reverse gear (electric on later models) and linked braking systems makes it an engineering marvel of accessibility and comfort. While the maintenance requirements are more intensive than a standard two-wheeler—specifically regarding rear differential checks and belt tension—the Tri Glide Ultra offers an unmatched level of stability for the serious cross-country traveler.