Shopping for motor oil can get confusing, and if you own more than one powersports vehicle, you might be curious if you can use the same lubricants in your V-twin, metric motorcycle, dirt bike, ATV and UTV. On the surface, it doesn’t seem like there’s much difference between motorcycle oil and ATV/UTV oil, or even the oil you put in your car.
However, different types of motorcycles and ATV/UTVs each present unique challenges to motor oil that one formulation can’t easily meet. Before we break them all down to see what makes them different, let’s look at what every motor oil must do regardless of the application.
Whether you ride a Harley-Davidson* touring bike, Kawasaki* sport bike, Honda* dirt bike, or Polaris* UTV, the oil must protect against wear and fight the damaging effects of heat. These effects include deposit formation, which robs the engine of efficiency and power. They also include oxidation, which is the chemical breakdown of the oil. The faster an oil breaks down, the quicker it loses its ability to guard against wear and deposits, which requires changing oil more frequently, wasting time and money.
That’s simple enough, and in the distant past, there was often only one motor oil available to protect all kinds of different vehicles. But modern engines are much more highly refined, and they will benefit from enhanced protection.
Powersports oil differences
The classic air-cooled V-twin engine, as found in most Harley-Davidson motorcycles, gets extremely hot. In our extreme-heat dyno test, we saw cylinder temperatures reach 420ºF (216ºC). That intense heat can wreak havoc on cheap motor oil, causing it to lose viscosity and become thinner, effectively turning your 20W-50 into a 10W-40, or worse. Running an engine on a lighter viscosity than it is designed for increases the risk of internal engine wear.
Extreme heat also hastens chemical breakdown, as the rate of oxidation doubles for every 18ºF (10ºC) increase in oil temperature. That means for every 18ºF increase in temperature, oil life is cut in half. It’s vital that the oil in your air-cooled V-twin is formulated to withstand such intense heat. To protect your V-twin, AMSOIL Synthetic V-Twin Motorcycle Oil is formulated with heat-resistant synthetic base oils that maintain viscosity despite extreme heat.
Bikes that use the same oil for both the engine and transmission are especially prone to viscosity loss as the force of transmission gears can also break down the oil’s molecular structure. AMSOIL Synthetic V-Twin Motorcycle Oil is shear stable and does not thin from mechanical activity, so it’s excellent at protecting your V-twin engine against wear and provides reliable protection under the toughest riding conditions.
AMSOIL Synthetic V-Twin Motorcycle Oil delivers excellent performance in the engine, transmission and primary chaincase, offering the convenience of a single oil for all three holes in your bike. It is available in 20W-40, 20W-50, 15W-60 and SAE 60 as part of our complete V-twin product line, including complete oil change kits with filter. For bikers who prefer to use oils formulated specifically for the transmission or chaincase, AMSOIL Synthetic V-Twin Transmission Fluid and Synthetic V-Twin Primary Fluid are engineered to the same exacting standards.
Metric motorcycle oil
Metric motorcycles are known for delivering high levels of performance and responsiveness. Metric single, twin, triple and four-cylinder engines, like those commonly found in standard (naked), cruiser, adventure (ADV), touring and sport bikes, can easily surpass 10,000 rpm. The mechanical action of the crankshaft spinning that fast can whip air into the oil, causing it to foam and lose its ability to coat the internal engine parts.
If the oil isn’t formulated with fast air-release properties, foam bubbles will travel throughout the engine. When they collapse between meshing gears or bearing surfaces, nothing is left behind except air, which provides zero protection against wear.
Smooth shifting is another important trait for metric motorcycles, most of which require wet-clutch-compatible lubricants to deliver efficient and consistent shift performance. Additionally, touring and ADV bikes aim to provide comfort, luxury and the adventure associated with long, cross-country trips, all of which benefit from extended drain intervals.
AMSOIL Synthetic Metric Motorcycle Oil is specifically formulated with anti-foam additives that weaken the surface tension of air bubbles, resulting in excellent wear protection. The advanced synthetic technology delivers excellent wet-clutch compatibility, enabling smooth shifts for a more comfortable ride and maximizes engine responsiveness to help you confidently push your bike to redline, for maximum speed, acceleration and cornering ability. It also extends drain intervals up to twice the bike manufacturer’s recommendations, allowing riders to confidently wander far from home.
AMSOIL Synthetic Metric Motorcycle Oil enhances performance and reliability and delivers superior protection against engine wear in high-performance engines. It is available in 10W-30, 10W-40 and 15W-50 as part of our complete metric motorcycle product line, including oil filters and AMSOIL Powersports Antifreeze & Coolant.
Dirt bike oil
Unsurprisingly, dual-sport and dirt bike operating conditions are more like that of an ATV or UTV. True, you don’t plow snow with your motorcycle, but the bike undergoes ample low-speed stress punctuated with periods of high revving. When racing, there’s frequent repetition between wide-open throttle on the straights and rapid acceleration through the corners. Throttling through jumps causes the rear tire to spin freely in the air, then create a heavy load on the engine when it contacts the ground. And trail riding requires lots of clutch and throttle manipulation to maneuver over and around obstacles.
Dirt bike engines are typically lightweight designs meant for performance. Any time you remove mass and increase power, you increase engine stress. The combination of high rpm and lighter materials creates the perfect scenario for engine failure if the motor oil fails to do its job.
Additionally, dirt bike pistons tend to have shorter piston skirts to reduce friction, which doesn’t help engine longevity. A shorter piston wants to rock inside the cylinder, which concentrates tremendous force on the tiny area where the piston skirt and cylinder wall contact. Only a microscopic oil film provides protection in this area, superior oil film strength is needed to help the engine survive.
Making matters worse, dirt bikes barely hold any oil, often only about one quart. That single quart of oil must fight wear, resist heat and prevent deposits. That is why most dirt bike riders change motor oil frequently, and in heavy use, the top-end may need to be rebuilt as often as every 15 hours!
AMSOIL Synthetic Dirt Bike Oil enhances engine performance and reliability, delivers superior protection against engine wear, and is far less expensive and less hassle than rebuilding your top-end. DOMINATOR® Synthetic 2-Stroke Racing Oil will handle all of your two-stroke needs, and oil for four-stroke dirt bikes is available in 10W-40, 15W-50 and 10W-60 as part of our complete dirt bike product line, including oil filters and AMSOIL Synthetic Dirt Bike Transmission Fluid.
ATVs and UTVs are the jack-of-all-trades when it comes to productivity. They can plow snow; herd livestock; haul dirt, gravel and rock; pull stumps; and help you move several cords of firewood every winter. They can alternately be used to joyride through the woods, mud, sand dunes or snow.
Motorcycles are typically ridden recreationally, at a consistent speed under light load, which creates less stress than pulling a stump out of the ground with your UTV or pulling a loaded trailer uphill through the mud with your ATV.
Oil film strength takes on additional importance in the hard-working world of ATVs and UTVs used to perform demanding chores at slow speeds and tackle tough terrain. They are frequently driven without shifting above first or second gear, pulling loaded trailers and other necessities to get the job done, in all types of weather on variable surface conditions.
Slow engine operation under heavy loads increases stress on the engine. If the oil’s film strength doesn’t hold up to increased pressure it will rupture, leading to increased wear. AMSOIL Synthetic ATV/UTV Motor Oil is engineered with robust synthetic base oils that allow formation of a durable protective film that maintains its strength under the toughest conditions.
AMSOIL purpose-built lubricants deliver cost-effective, high-performance alternatives in the same viscosity specifications as most OEM-branded ATV/UTV fluids, including 10W-30, 10W-40, 5W-40, 5W-50, 0W-40 and 0W-50 as part of our complete ATV/UTV product line, including complete oil change kits with filter.
What’s right for my vehicle?
There are significant differences in the usage of different types of motorcycles, ATVs and UTVs. Each application creates unique challenges that are best suited for a tailor-made motor oil formulation. If you aren’t sure which products are right for your vehicle, no worries, we’ve got you covered! Click the banner below to visit our vehicle lookup guides and get the best products to protect your machines.
AMSOIL Technical Writer and 20-year veteran of the motorcycle industry. Enjoys tearing things apart to figure out how they work. If it can’t be repaired, it’s not worth owning.