AMSOIL 10W-50 100% Synthetic Dirt Bike Oil
AMSOIL INC., the premier manufacturer of synthetic motorcycle lubricants, focuses on improving lubricant performance so riders can focus on improving their performance on the trail or track. That's why AMSOIL is the choice of professional riders and weekend warriors everywhere.
Quart Bottles, Case of 12
Quart Bottle
Product highlights
AMSOIL INC., the premier manufacturer of synthetic motorcycle lubricants, focuses on improving lubricant performance so riders can focus on improving their performance on the trail or track. That's why AMSOIL is the choice of professional riders and weekend warriors everywhere.
Delivers Confidence in Clutch Feel
AMSOIL Synthetic Dirt Bike Oil's superior friction-durability properties help minimize clutch slippage, fade and chatter, giving riders consistent clutch feel during takeoffs or when maneuvering around obstacles on the trail. In an extreme simulated-start test, AMSOIL Synthetic Dirt Bike Oil continued to deliver consistent clutch feel following 32 simulated race starts, while a leading original equipment manufacturer (OEM)-branded oil demonstrated inconsistent clutch-lever action and poor clutch feel after 16 starts. The clutch plates lubricated with AMSOIL Synthetic Dirt Bike Oil remained clean and in good overall condition, while the plates using the OEM oil revealed discoloration and wear. AMSOIL Synthetic Dirt Bike oil's superior performance helps instill in riders the confidence that their bikes will perform consistently in all types of riding conditions.
Protects Against Wear
AMSOIL Synthetic Dirt Bike Oil withstands high-rpm operation, extreme heat and mechanical shear. Its synthetic base oils naturally resist viscosity loss and provide a protective film against wear to gears, bearings and pistons. Its anti-wear additives provide an extra measure of protection, promoting long component life to help riders get the most out of their bikes.
Delivers confidence in clutch feel
Superior protection against gear, bearing & piston wear
Maximizes horsepower
Helps extend clutch life

RACING IS RESEARCH™
AMSOIL Synthetic Dirt Bike Oil underwent extensive on-track testing in the bikes of professional riders. A combination of racer feedback and lab testing allowed AMSOIL to fine-tune AMSOIL Synthetic Dirt Bike Oil for outstanding wear protection and consistent clutch feel ‐ benefits riders demand.
APPLICATIONS
Use 10W-50 Synthetic Dirt Bike Oil in dirt bikes that require 10W-50 motorcycle oil, including those made by KTM*, Kawasaki, Yamaha, Suzuki and Husqvarna. JASO MA; API SG, SJ, SH, SL.
SERVICE LIFE
AMSOIL Synthetic Dirt Bike Oil should be changed according to the vehicle manufacturer's recommendations.
COMPATIBILITY
AMSOIL Synthetic Dirt Bike Oil is compatible with other synthetic and conventional motor oils. Adding other oils, however, will shorten the life expectancy of AMSOIL motor oils and reduce their performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed. Aftermarket oil additives are not recommended for use with AMSOIL Synthetic Dirt Bike Oil.
WARRANTY SECURE
AMSOIL Synthetic Dirt Bike Oil is Warranty Secure, keeping your factory warranty intact. AMSOIL Synthetic Dirt Bike Oil is a high-performance replacement for vehicle manufacturer-branded products and is also backed by the AMSOIL Limited Warranty. For details, visit www.amsoil.com/warranty/.

HEALTH & SAFETY
This product is not expected to cause health concerns when used for the intended applications and according to the recommendations in the Safety Data Sheet (SDS). An SDS is available via the Internet at www.amsoil.com or upon request at (715) 392-7101. Keep Out of Reach of Children. Recycle used oil and bottle.
APPLICATIONS
Use 10W-50 Synthetic Dirt Bike Oil in dirt bikes that require 10W-50 motorcycle oil, including those made by KTM*, Kawasaki, Yamaha, Suzuki and Husqvarna. JASO MA; API SG, SJ, SH, SL.
100% Synthetic Dirt Bike Oil
Designed to Improve Bike and Rider Performance
AMSOIL Synthetic Dirt Bike Oil is specifically engineered to provide superior clutch engagement and engine reliability in severe conditions, making it the best choice for professional riders and weekend warriors focused on improving performance on the trail or track. Whether launching the holeshot, roosting corners, overcoming obstacles or navigating tight turns deep in the woods, it delivers the performance attributes that dirt bike riders demand, including smooth, confident and consistent clutch engagement from start to finish.
Consistent Clutch Feel
The superior friction-durability properties of AMSOIL Synthetic Dirt Bike Oil help eliminate clutch slippage, fade and chatter to provide consistent clutch feel during launches and when maneuvering over and around obstacles. In extreme testing, AMSOIL Synthetic Dirt Bike Oil continued to deliver consistent clutch engagement following 32 simulated race starts, while a leading motorcycle manufacturer-branded (OEM) oil demonstrated inconsistent clutch-lever action and poor clutch engagement after only 16 starts. The clutch plates lubricated with AMSOIL Synthetic Dirt Bike Oil remained clean and in good condition, while the plates using the OEM oil revealed discoloration and wear. AMSOIL Synthetic Dirt Bike Oil delivers superior clutch performance, giving riders confidence that their bikes will deliver predictable power when they need it most.
Protects Against Wear
The synthetic base oils in AMSOIL Synthetic Dirt Bike Oil naturally resist mechanical shear and viscosity loss, maintaining a thick protective film that helps prevent metal-to-metal contact under high-rpm operation and extreme heat. Its premium anti-wear additives provide an extra measure of protection against gear, bearing and piston wear that helps reduce maintenance and extend clutch and engine life.
- Delivers consistent clutch feel
- Protects against gear, bearing and piston wear
- Maximizes horsepower
- Helps extend clutch life

RACING IS RESEARCH™
AMSOIL Synthetic Dirt Bike Oil was extensively performance tested by professional riders in their race bikes. A combination of racer feedback and lab testing was used to fine-tune the formula to deliver maximum anti-wear protection and consistent clutch feel – key benefits that dirt bike riders demand.
SERVICE LIFE
AMSOIL Synthetic Dirt Bike Oil should be changed according to the vehicle manufacturer’s recommendations.
COMPATIBILITY
AMSOIL Synthetic Dirt Bike Oil is compatible with other synthetic and conventional motor oils. However, adding other oils will shorten the life expectancy of AMSOIL motor oils and reduce their performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed. Aftermarket oil additives are not recommended for use with AMSOIL Synthetic Dirt Bike Oil.
Technical Properties
| Property | DB50 |
|---|---|
| Kinematic Viscosity @ 100°C, cSt (ASTM D445) | 18.1 |
| Kinematic Viscosity @ 40°C, cSt (ASTM D445) | 120.8 |
| Viscosity Index (ASTM D2270) | 167 |
| Flash Point, °C (°F) (ASTM D92) | 246 (475) |
| Fire Point, °C (°F) (ASTM D92) | 272 (522) |
| Pour Point, °C (°F) (ASTM D97) | -38 (-36) |
| NOACK Volatility, % weight loss (g/100g) (ASTM D5800) | 4.1 |
| High-Temperature/High-Shear Viscosity @ 150°C, 1.4 X 10⁶ s⁻¹, cP (ASTM D5481) | 4.9 |
| Four-Ball Wear Test (ASTM D4192 @ 40 kgf, 150°C, 1800 rpm, 1 hr) scar, mm | 0.52 |
| Foam (ASTM D5182, Sequence I, II & III) | 0/0, 20/0, 0/0 |
| Total Base Number | 7.6 |
Dirt Bike Clutch Testing
Customer Reviews
5.0 out of 5 from 188 reviews
So far so good
I only have a couple hundred miles using this oil, but so far it seems to be doing well. I highly trust putting Amsoil products in my motorcycle and cars.
Great wear protection!
I use this in all my dirt bikes. It quiets down every engine I put it in. Never had a clutch slip. I do oil changes ever 4-6hrs of moderate track riding. 2011 crf450r, '16 crf250r, '23 kx65, '22 crf50
Smooth as Silk
I was running MAXIMA 10-40w 4 stroke...With this 06 yz450 has a Problem from shifting from Third to Fourth when RPM`s are high...Its common with 06,07.....But did some researching...Had a Motocross Racer suggest running AMSOIL 10w-40 weight for better low friction from Third to Fourth.....So far Hauling Ass....Thanks # 007
Atv
Fantastic oil my Honda ATV ran so smoothly after using this oil.
Great Oil
I have run this oil in all my bikes for several years and no complaints at all, all valves stay within spec etc no clutch concerns and do like the clutch feel with the oil.
Oil
AMSOIL who is the best I use it in my XR 250 R Honda my Honda four wheeler and all my Harley’s the only drawback is that it’s very expensive I would run it in my Ford 7.3 diesel but that takes 15 quarts would cost over [price removed] for oil that’s just too much.
10W-40 dirt bike oil
Great product, been using this on a 2024 Honda CRF150R since new. Changed regularly due to racing the bike. Seems to hold up very well. Will continue to use it.
Dirtbikes
We use it in all of our 2 strokes transmissions..keeps the clutch feeling new, and have not had a single issues since we started using this product
Dirt Oil for dirt bikes
I use Amsoil Dirt 10W-40 in my 2024 Honda CRF450, changing every 5 hours. No issues in two years of riding , 75 hours total. This oil adds to the dependability of my bike allowing me to concentrate on my riding, great product!
Great oil for 4- stroks
Transmission shifts better
