| Parameter | Specification |
|---|---|
| Model Series | SC79D/25 (2018-Present) |
| Engine Type | 1833cc Liquid-cooled Flat-Six |
| Transmission | 7-Speed Dual Clutch Transmission (DCT) |
| Engine Oil | SAE 10W-30 JASO T 903 MA (Non-Moly) |
| Oil Capacity | 4.6 Liters |
| Tire Size (F/R) | 130/70R18 / 200/55R16 |
| Spark Plugs | NGK SILMAR8C-9 |
| Battery | GYZ20L |
The Engineering Paradigm Shift: Double Wishbone Front End
While the Gold Wing has always been the benchmark for luxury touring, the SC79 generation introduced a radical engineering departure: the Double Wishbone Front Suspension. Moving away from traditional telescopic forks, this automotive-style setup separates the steering function from the suspension damping. This reduces friction by up to 30% and keeps the wheelbase consistent under heavy braking, providing the SC79 with agility that defies its massive footprint.
DCT Maintenance: The ‘Non-Moly’ Mandate
The 7-speed DCT in the GL 1800 is a marvel of hydraulic logic, but it is highly sensitive to oil chemistry. MotoSpecsLab emphasizes the use of SAE 10W-30 JASO T 903 MA oil. Crucially, the oil must be Non-Moly (free of molybdenum friction modifiers). Molybdenum can cause the clutch packs within the DCT to slip, leading to gear engagement errors and premature wear. A full service requires 4.6 liters of oil and specific DCT filter replacement alongside the standard engine oil filter.
Chassis and Contact Patch
The SC79D/25 utilizes a massive 200-section rear tire to handle the 170 Nm of torque. Maintaining precise pressures of 2.5 bar (36 psi) front and 2.8 bar (41 psi) rear is mandatory for tire longevity and to prevent ‘cupping’—a common issue on heavy tourers. The NGK SILMAR8C-9 Iridium plugs are designed for long service intervals but should be inspected for gap consistency to ensure the smooth, rhythmic idle the flat-six is known for.
MotoSpecsLab Verdict
The Honda GL 1800 Gold Wing DCT SC79D/25 is less of a motorcycle and more of a precision-engineered land-yacht. For the owner-mechanic, adherence to the specific oil grade and DCT filtration is the single most important factor in preserving the legendary Honda reliability. It remains the gold standard for long-distance technical excellence.