Different types of motorcycles present unique challenges to motor oil that a single formulation cannot easily meet.

Customers who own more than one motorcycle might be curious if they can use the same lubricants in their V-twin, metric motorcycle and dirt bike. However, there are significant differences in the usage of different types of motorcycles and each application creates unique challenges that are best suited for a tailor-made engine-oil formulation.

Motorcycle oil must protect the engine and transmission against wear and fight the damaging effects of extreme heat, including deposit formation that robs the engine of efficiency and power, and oxidation that causes chemical breakdown of oil. The faster an oil breaks down, the quicker it loses its ability to guard against wear and deposits. Let’s look at what makes AMSOIL motorcycle oils different.

V-twin

Classic air-cooled V-twin engines get extremely hot. In dyno testing, we saw cylinder temperatures reach 420ºF (216ºC). That intense heat wreaks havoc on cheap motor oil, causing it to lose viscosity and become thinner. Running an engine on a lighter viscosity than specified increases the risk of internal engine wear.

Extreme heat also hastens chemical breakdown, as the rate of oxidation doubles for every 18 degrees fahrenheit (10 degrees celsius) increase in oil temperature, oil life is cut in half. To protect hot V-twin engines, 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 in the engine, transmission or primary chaincase, offering the convenience of a single oil for most V-twins.

Metric

Adventure(ADV), touring and sport bikes are known for delivering performance and responsiveness, with high-revving engines that 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. When foam bubbles collapse between meshing gears or bearing surfaces, only air remains, providing no protection against wear.

Most metric motorcycles also have wet clutches that require compatible lubricants to deliver smooth, efficient and consistent shift performance. Touring and ADV bikes are designed to be comfortable for long, cross-country trips, which benefit from extended drain intervals.

AMSOIL Synthetic Metric Motorcycle Oil is formulated with anti foam additives that help prevent the formation of air bubbles, resulting in excellent wear protection. Its advanced synthetic technology delivers excellent wet-clutch compaibility, enables smoother shifts and maximizes engine responsiveness to help riders confidently achieve maximum speed, acceleration and cornering ability. It also extends drain intervals up to twice the bike manufacturers recommendations, allowing riders to confidently wander far from home.

Dirt Bikes

Dual-sports and dirt bikes undergo ample low-speed stress punctuated with periods of high revving. Racing requires frequent repetition between wide-open throttle on the straights and rapid acceleration through the corners. Jumping causes the rear wheel to spin freely followed by a heavy load on the engine when it contacts the ground. Trail riding requires lots of clutch and throttle manipulation to maneuver over and around obstacles.

Dirt bike engines are typically extremely lightweight, high performance designs, but removing mass and increasing power also increases engine stress. The combination of high rpm and lighter materials creates the perfect scenario for engine failure. Dirt-bike pistons tend to have shorter skirts to reduce friction, with only a microscopic oil film providing protection. 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. We’ve seen dirt-bike pistons crack after barely 100 hours of use. Making matters worse, dirt bikes only hold about one quarts of oil to fight wear, resist heat and prevent deposits. Most dirt-bike riders change oil frequently. In heavy use, the engine top-end may need to be rebuilt as often as every 15 hours.

AMSOIL Synthetic Dirt Bike Oil is designed to deliver superior protection against engine wear under extreme stress, enhancing four-cycle engine performance and reliability, plus it is far less expensive and less hassle than rebuilding your top end. AMSOIL DOMINATOR Synthetic 2-Stroke Racing Oil provides two-stroke riders with the same level of engine protection.