Can I mix the old metric oil with the new 100% synthetic?

Yes. Both formulas are fully compatible. No engine flush needed. You can safely transition to the new formula at your next scheduled oil change.

Which viscosity does my bike need?

Check your owner's manual for the correct viscosity. Most Honda, Kawasaki, Suzuki, and Yamaha use 10W-40 (MCF). BMW and Triumph often use 10W-40 or 5W-40. Adventure bikes like KTM and Husqvarna use 10W-50 (MSR).

Can I use old stock of metric oil?

Yes. Previous AMSOIL Synthetic Metric Oil remains a solid choice. Both old and new formulas are backward-compatible. You can use what you have and transition to the new formula when ready.

Motorcycle oil rebrand 2026 | AMSOIL Upgrades Metric Motorcycle Oil | New 100% Synthetic Formula

Starting May 26, 2026, AMSOIL is officially rebranding its Metric Motorcycle Oil line to 100% Synthetic Motorcycle Oil. For riders of Honda, Kawasaki, Suzuki, Yamaha, BMW, Triumph, and other metric bikes, this is more than just a name change. It's a formula upgrade with improved heat resistance and better protection for modern liquid-cooled engines.

Motorcycle oil rebrand 2026 | What's New for Your Bike?

The new 100% Synthetic label guarantees a pure synthetic base with no conventional oil fillers. AMSOIL has reformulated the line to exceed the latest API SN and JASO MA/MA-2 standards—meaning better performance where it counts: in your engine.

What riders will notice:

Crisper Shifting: Enhanced viscosity stability keeps your clutch and transmission smooth under load.
Cooler Operation: Superior heat resistance for stop-and-go traffic and summer highway touring.
Engine Cleanliness: Advanced detergency fights carbon deposits in high-revving engines.
Anti-Foam: Prevents oil aeration at high speeds, ensuring consistent lubrication even at the track.

Which Oil Does Your Bike Need?

AMSOIL offers five viscosity grades. Check your owner's manual for the exact spec your bike calls for. When in doubt, the 10W-40 (MCF) works for the vast majority of metric bikes.

MCT — 10W-30: Lighter viscosity for newer Honda and Yamaha models. Excellent fuel economy and fast oil flow during winter cold starts.
MCF — 10W-40: The most common choice across Japanese and European metric bikes—Honda, Kawasaki, Suzuki, Yamaha, and many others. Balanced protection for street riding.
MMF — 5W-40: For riders in cold climates and many BMW, Can-Am, and Triumph models. Flows instantly in winter but maintains a thick protective film when hot.
MFF — 15W-50: Heavy viscosity for big-bore European twins and bikes that run hot: Ducati, KTM, Royal Enfield. Maximum film strength for sustained heat.
MSR — 10W-50 (NEW): Built for adventure and dual-sport riders. The viscosity of choice for KTM and Husqvarna adventure bikes and other metric platforms requiring extra high-temperature protection across diverse terrain.

Pro Tip: You don't need to flush your engine. If you have a quart of the "old" Metric Oil sitting in your garage, you can safely use it up or transition to the new 100% Synthetic formula at your next oil change. Both are fully compatible—no special procedures needed.

Adventure Riders: Meet MSR 10W-50

If you ride a KTM or Husqvarna adventure bike—or any metric platform designed for diverse terrain—AMSOIL's new MSR 10W-50 is engineered specifically for you. Adventure bikes operate across extreme conditions: high-altitude cold starts, sustained heat during climbing, rapid cooling in mountain passes, and shock loads from off-road terrain.

The 10W-50 viscosity delivers fast cold-start protection at elevation while maintaining a thick film under sustained heat. It resists foaming under continuous high-RPM operation and fights wear from the constant shock loads of off-road riding.

Frequently Asked Questions

Do I need to flush my engine before switching?

No. The new 100% Synthetic formula is fully backward-compatible with the previous AMSOIL Synthetic Metric Motorcycle Oil. Simply drain and refill at your next scheduled service. No special procedures needed.

Can I mix old and new oil?

Yes. Both formulas are compatible. You can safely run them together during the transition. That said, it's cleaner to drain the old oil completely at your next service and refill with the new formula.

What's the difference between 10W-40 and 10W-50?

Both have the same cold-start flow (10W), but 10W-50 is thicker when the engine is hot. Use 10W-40 for standard metric street bikes. Use 10W-50 for adventure/dual-sport bikes or if your owner's manual specifies it.

How do I know which viscosity my bike needs?

Check your owner's manual. It will specify the exact viscosity (e.g., 10W-40, 5W-40). When in doubt, 10W-40 (MCF) is the most common across metric bikes. If your bike is from a cold climate region or is a high-heat platform, your manual will guide you to a different grade.

What does "JASO MA-2" mean?

JASO MA-2 is a Japanese standard for motorcycle oils used in wet clutches and modern emission systems. In practical terms: smooth, crisp shifting without clutch slippage, even under hard acceleration. It also means the oil won't foul catalytic converters or oxygen sensors.

Is the new formula better than the old metric oil?

Yes. The new formula meets the latest API SN and JASO MA-2 standards with measurable improvements: better heat resistance, improved foaming control at high RPM, and enhanced engine cleanliness. It's a real upgrade over the previous Metric formula.

Is the old metric oil still good?

Yes. If you still have stock of the previous AMSOIL Synthetic Metric Motorcycle Oil, it remains a solid, proven product. You can use it without hesitation. There's no rush to switch—transition to the new formula when you're ready for your next oil change.

Get the New Formula

Give your bike the 100% Synthetic advantage. Available starting May 26, 2026.

Shop 100% Synthetic Motorcycle Oil