AMSOIL Motorcycle Octane Boost
AMSOIL Motorcycle Octane Boost (MOB) is a 4-ounce, motorcycle-specific octane booster formulated for four-stroke air- and liquid-cooled bikes, including high-compression V-Twins from Harley-Davidson and metric sport, adventure, and touring models. One bottle treats a single tank, so the dose lines up with the small fuel capacities typical of motorcycles instead of car-sized bottles that overshoot or get rationed across multiple fills.
Up to a three-number Research Octane lift per bottle
Added to 4 to 6 gallons of fuel, Motorcycle Octane Boost raises Research Octane Number (RON) by as many as three numbers. The reference test moves baseline gasoline from 92.6 RON to 95.6 RON, the same magnitude printed on the bottle. RON is the rating used in industry validation work and runs a few numbers higher than the Anti-Knock Index ((R+M)/2) shown on North American gas pumps, where 87-octane regular usually corresponds to about 91 to 92 RON.
Some additive brands market octane gains on a "points" scale where ten points equals one full octane number. The three-number lift listed for Motorcycle Octane Boost is reported in full octane numbers, not points, so the rating compares directly to the RON values quoted by fuel chemists and engine calibrators.
Reclaims power lost to knock and ping
Engine knock, the audible pinging caused by uncontrolled, early ignition of fuel in the combustion chamber, robs power and can cause catastrophic engine damage if it continues. Knock shows up most often during idle, low-rpm operation, and high-temperature riding, exactly the conditions that punish air-cooled V-Twins in summer traffic and high-compression sport bike engines on borderline pump fuel. Raising effective octane removes the underlying cause instead of relying on engine controls to mask it.
Restores low-rpm output on knock-controlled bikes
Modern motorcycle engines use knock-detection systems that retard spark timing and adjust the air-to-fuel mixture until knock stops. The protection works, but it also reduces horsepower and dulls low-rpm response. Motorcycle Octane Boost lifts the fuel above the knock threshold so the knock-control strategy has less to correct, which preserves throttle response, low-rpm pull, and torque feel through the gearbox.
Detergency for combustion chambers and fuel delivery
The MOB formula carries active detergents that help keep combustion chambers, intake valves, injectors, and carburetor circuits free of varnish and deposit film, supporting consistent burn quality and full-rated efficiency over time. For heavier deposit cleanup, particularly in ethanol-affected powersports fuel systems, AMSOIL Quickshot uses a higher concentration of cleaning agents and pairs naturally with Motorcycle Octane Boost as a maintenance program.
Catalyst, oxygen sensor, and additive compatibility
At the recommended treat rate, Motorcycle Octane Boost does not harm catalytic converters or oxygen sensors, so it suits late-model bikes that depend on closed-loop fuel control and emissions-compliant exhaust hardware. The product is also compatible with all other AMSOIL fuel additives, which means a rider can stack it with Quickshot for ethanol protection and deposit cleanup without conflict.
Recommended applications and service intervals
One 4-oz. bottle of Motorcycle Octane Boost treats 4 to 6 gallons of gasoline. Pour the bottle in before the fuel goes in so the additive mixes thoroughly during the fill. Use is on-demand rather than every-tank: dose when knock or ping appears, when only lower-octane fuel is available, or before extended high-load riding such as two-up touring, mountain runs, or hot-weather stop-and-go traffic.
- Primary application match: four-stroke air- or liquid-cooled motorcycles, including Harley-Davidson, Yamaha, Honda, Ducati, BMW, Triumph, and other four-stroke street, touring, sport, and adventure bikes.
- Off-road alternative: ATVs, UTVs, and snowmobiles when AMSOIL DOMINATOR Octane Boost is not on hand. DOMINATOR Octane Boost remains the preferred choice for high-output off-road and racing applications.
- Compatibility: works with all other AMSOIL fuel additives, including AMSOIL Quickshot for ethanol-affected fuel and deposit cleanup.
- Spills: clean immediately with a clean towel. If left standing, the concentrate can stain painted or metal surfaces.
Match the right product to the bike with the vehicle lookup guide before pairing additives with a specific engine, and match the additive program with the right base lubricant from the motorcycle oil guide for V-Twin or metric service.
Typical use specifications
| Property | Value |
|---|
| Treat rate | One 4-oz. bottle per 4 to 6 gallons of gasoline |
| Octane increase | Up to 3 Research Octane Numbers (RON) |
| Reference RON shift | 92.6 RON to 95.6 RON |
| Catalytic converter and oxygen sensor compatibility | Safe at recommended treat rate |
| AMSOIL fuel additive compatibility | Compatible with all AMSOIL fuel additives |
| Primary application | Four-stroke air- or liquid-cooled motorcycles |
Order Motorcycle Octane Boost
Available in a 4 oz. bottle (product code MOBCN-EA) and a case of twelve 4 oz. bottles (MOBCN-CA), AMSOIL Motorcycle Octane Boost is backed by the AMSOIL Limited Warranty. Match the right base oil first using the motorcycle oil guide and match the right product to the specific bike with the vehicle lookup guide, then place an order for AMSOIL Motorcycle Octane Boost.
Customer reviews
Harley Davidson
The best product i had ever used.
By Mike from GoodYear, AZ on July 15, 2026.
Would recommend this to a friend.
Great Product
My motorcycle seems to like it alot. It runs much better.
By Kevin from Pa. on July 03, 2026.
Would recommend this to a friend.
XR200
First time to use it and I noticed an immediate difference in the horsepower on my XR200. I poured half the bottle directly into my fuel tank. No engine pings or knocks. The bike bike actually ran cooler!
By Milam from Houston on May 26, 2026.
Would recommend this to a friend.
Read all 158 reviews
Frequently asked questions
How much does Motorcycle Octane Boost raise octane?
One 4-oz. bottle in 4 to 6 gallons of gasoline raises Research Octane Number (RON) by as many as three full numbers, moving the reference fuel from 92.6 RON to 95.6 RON. RON values run a few numbers higher than the AKI value posted on North American gas pumps, since pump AKI is the average of RON and MON.
Does it work in V-Twin Harley-Davidson and Indian engines?
Yes. Motorcycle Octane Boost is formulated for four-stroke air- or liquid-cooled motorcycles, including Harley-Davidson and other V-Twin platforms. The dose is sized to a typical motorcycle tank, and the higher effective octane helps eliminate knock or ping that high-compression V-Twins can produce on lower-grade pump fuel, especially in hot weather and at low rpm.
Will it harm catalytic converters or oxygen sensors?
No. At the recommended treat rate of one 4-oz. bottle per 4 to 6 gallons of gasoline, Motorcycle Octane Boost does not harm catalytic converters or oxygen sensors, which makes it appropriate for late-model bikes that rely on closed-loop fuel control and emissions hardware.
Can it be used in ATVs, UTVs, or snowmobiles?
It can. Motorcycle Octane Boost is approved for off-road use in ATVs, UTVs, and snowmobiles as an alternative to AMSOIL DOMINATOR Octane Boost. DOMINATOR Octane Boost remains the preferred choice for high-output off-road and racing engines that benefit from a stronger formulation.
Can it be combined with AMSOIL Quickshot or other fuel additives?
Yes. Motorcycle Octane Boost is compatible with all other AMSOIL fuel additives. Pairing it with AMSOIL Quickshot stacks on-demand octane lift with a higher-detergent cleanup formula that targets ethanol-related issues in powersports fuel systems.
Does it clean injectors and carburetor circuits?
The formula contains active detergents that help maintain combustion-chamber and fuel-delivery-system cleanliness for steadier efficiency. For heavier deposit cleanup, or after long off-season storage, AMSOIL Quickshot is the better choice because it carries a greater concentration of cleaning agents.
How should spills on the bike be handled?
Clean spills right away with a clean towel. If Motorcycle Octane Boost is left standing on painted or metal surfaces, it can stain. Cleaned immediately, no lasting damage occurs.
