AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil
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Premium Protection for Engines, Transmissions and Primary Chaincases
AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil is a premium oil designed for those who demand the best protection for their motorcycles. It is specially formulated to excel in all areas unique to motorcycles, including the high temperatures of air-cooled engines such as Harley-Davidson V-twins, wet-clutch lubrication, extreme-pressure regions of gears and chains, and rust common to short trips and storage. AMSOIL Synthetic V-Twin Oil is multi-functional and fills the requirements of both domestic and foreign motorcycles.
Key Benefits
- Resists extreme heat in air-cooled V-twin engines
- Resists viscosity breakdown 6X better than Harley-Davidson SYN3
- One lubricant for engine, transmission and primary chaincase
- Heavy anti-wear additives protect against piston scuffing and ring sticking
- Superior rust protection passes ASTM D1748 humidity cabinet test
- Excellent wet-clutch performance with no friction modifiers
- Warranty Secure — keeps factory warranty intact
- Up to 2X manufacturer-recommended drain interval
Reduces Wear and Deposits in Extreme Heat
Big, powerful V-twin engines run extremely hot, especially in summer during stop-and-go, rally or parade traffic. High heat breaks down oil formulated for standard service, inviting wear and performance-robbing deposits.
AMSOIL Synthetic V-Twin Motorcycle Oil is formulated with naturally heat-resistant synthetic base oils that resist oxidation in extreme heat. It contains a heavy treatment of anti-wear additives to reduce wear regardless of operating conditions. After 1,000 miles (1,609 km) of dyno testing during which oil temperature reached 300°F (149°C) and cylinder temperature reached 421°F (216°C), AMSOIL V-Twin Oil fought piston-ring deposits to prevent sticking and protected against piston scuffing for maximum compression and power.
AMSOIL V-Twin Oil delivers exceptional protection in transmissions and primary chaincases. It is shear stable and resists viscosity breakdown 6X better than Harley-Davidson SYN3 for improved protection against compensator and transmission gear wear.
Technical Specifications
| Property | Value |
|---|---|
| Kinematic Viscosity @ 100°C, cSt | 18.5 |
| Kinematic Viscosity @ 40°C, cSt | 132.8 |
| Viscosity Index | 156 |
| Pour Point | -41°C (-42°F) |
| Flash Point | 228°C (442°F) |
| High-Temperature/High-Shear Viscosity @ 150°C, cP | 5.6 |
| Four-Ball Wear Test Scar, mm | 0.37 |
| FZG Load Stage Pass (Wear in mm) | 12+ (0 mm) |
| NOACK Volatility, % weight loss | 4.2 |
| Foam (Sequence I, II, III) | 0/0, 20/0, 0/0 |
| Rust Test — Humidity Cabinet | No Rust, Pass |
| Total Base Number | 11.6 |
Industry Certifications & OEM Approvals
JASO
- MA/MA-2
API
- SL, SH, SG, CG-4, CF
ISO
- ISO-L-EMA2
Applications & Specifications
Use in motorcycles that require 20W-50 motorcycle oil, including those made by Harley-Davidson and Buell. Suitable for use in motorcycles that require an API CH-4 oil.
JASO MA/MA-2 • API SL, SH, SG, CG-4, CF • ISO-L-EMA2
Do not use where an API GL-4 or GL-5 gear oil is required.
Service life: Up to 2X the motorcycle manufacturer change interval or one year, whichever comes first, in engines, transmissions and primary chaincases. For Big Twin Harley-Davidson transmissions only, follow the H-D recommended drain interval for synthetic oil of up to 20,000 miles or one year.
Pros and Cons
Pros
- Resists extreme heat in air-cooled V-twin engines
- Resists viscosity breakdown 6X better than Harley-Davidson SYN3
- One lubricant for engine, transmission and primary chaincase
- Heavy anti-wear additives protect against piston scuffing and ring sticking
- Superior rust protection passes ASTM D1748 humidity cabinet test
- Excellent wet-clutch performance with no friction modifiers
- Warranty Secure — keeps factory warranty intact
- Up to 2X manufacturer-recommended drain interval
Cons
- Premium Investment: Higher initial cost compared to conventional or "shelf-brand" synthetic oils.
- Limited Local Retail: Primarily available through authorized dealers and specialized synthetic outlets. National Synthetics is a local stocking dealer. Call 1-678-944-8816 to confirm in-stock items for same-day local pickup.
Order Through Your Independent AMSOIL Dealer
Give your V-twin the protection it deserves. As your Independent AMSOIL Dealer, we provide expert guidance and competitive pricing on all AMSOIL products.
Independent AMSOIL Dealer #30576570
Shipping & Returns
Fast, Reliable Shipping
- Free standard ground shipping on orders of $100 ($130 in Canada) or more.
- Orders under the threshold ship for a flat $9.99 ($12.99 in Canada) freight charge.
- In-stock items typically delivered in two to three business days.
- U.S. and Canada only — no shipments to PO Boxes.
30-Day Return Policy
- Return unopened, currently marketed products within 30 days for a full refund (minus freight).
- Exchange unopened products within 90 days with no restocking fee.
- Special-order items are non-returnable.
- Returns are handled directly by AMSOIL.
Frequently Asked Questions
Yes. AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil is a multi-functional lubricant designed for use in all three sumps — engine, transmission and primary chaincase. It eliminates the need for separate lubricants and provides excellent protection in all three applications.
In CEC L45-KRL (ASTM D445) testing, AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil resists viscosity breakdown 6X better than Harley-Davidson Screamin' Eagle SYN3, providing improved protection against compensator and transmission gear wear.
Use for up to 2X the motorcycle manufacturer change interval or one year, whichever comes first, in engines, transmissions and primary chaincases. For Big Twin Harley-Davidson transmissions only, follow the H-D recommended drain interval for synthetic oil of up to 20,000 miles or one year. When not using an AMSOIL Motorcycle Oil Filter, change the filter at standard intervals.
Yes. AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil contains no friction modifiers and promotes smooth shifting and positive clutch engagement. It controls heat and helps prevent slippage and glazing, while its high TBN helps improve clutch life by resisting acids that degrade clutch material.
Customer Reviews
See all 1,572 reviewsRoad Glide Limited
This Oil Works great, When On the Run For The Wall 2025 on my 2020 Harley Road Glide Limited and loaded it down and drove over 6800 Miles on a fresh oil change, and Oil still looked dam good. Only oil I will use on my motorcycles, Cars, Truck and boat. Love It Thanks for a great Oil
Independent AMSOIL Dealer #30576570. Product information sourced from AMSOIL. Visit AMSOIL.com for the most current product details and availability.