What does extreme heat do to motorcycle oil?
The short answer: As heat intensifies, motor oil loses viscosity and becomes thinner. The oil can become so thin that the engine loses oil pressure and you may hear increased valvetrain and gear noise as the metal parts clatter together.
Extreme summer heat combined with slow-moving commute, rally or parade traffic can be a big problem for your motorcycle.
As heat intensifies, motor oil loses viscosity and becomes thinner. The oil can become so thin that the engine loses oil pressure and you may hear increased valvetrain and gear noise as the metal parts clatter together. Riding with low oil pressure can damage the engine and the only solution is to shut the bike off and wait until the engine cools enough to restore oil pressure.
Decreased airflow
Air-cooled V-twins get extremely hot and riding in slow-moving traffic makes it even worse. When idling, the heat generated by the front cylinder makes the rear cylinder even hotter. Crawling along barely above idle doesn’t generate enough airflow to keep the engine cool. Add in the blazing heat reflecting off the asphalt and it’s a recipe for trouble.
Heat breaks down oil
It’s the motor oil’s job to protect the engine from exposure to intense heat. The rate at which oil oxidizes, or chemically breaks down, doubles for every 18°F (10°C) increase in lubricant temperature. Oxidation occurs when oxygen molecules attack oil molecules resulting in a chemical reaction that leads to harmful byproducts like sludge and varnish. The faster the oil oxidizes, the sooner it wears out and requires changing.
Additionally, oil thins as it heats up and if it becomes too thin it can’t prevent metal components from contacting during engine operation. Once the lubricant film fails, only a sacrificial layer of anti-wear additives on the components is left to prevent wear. But these additives are designed to deplete with time and use. Once they wear out, your engine isn’t protected anymore.
Better Protection
Extreme summer heat causes inferior oils to lose viscosity, which leads to poor shift quality, compensator noise and potential engine and transmission wear.
Hot oil can become so thin that your engine loses oil pressure, and you might even hear valvetrain and gear noise as metal parts clatter together. Riding with low oil pressure can damage your engine, and the only solution is to shut your bike off and wait until the engine cools off to restore oil pressure.
Oil that maintains its viscosity leads smoother, more confident shifting and helps prevent compensator noise and engine wear.
AMSOIL Synthetic V-Twin Motorcycle Oil fights the viscosity-destroying effects of extreme engine heat during hot summer riding. In fact, it provides 6X better viscosity stability than Harley-Davidson SYN3.*
Ride Hard. Run Cool.®
The normal operating temperature of a motorcycle engine is between 155°F and 230°F degrees Fahrenheit (68°C to 110°C). This range can vary depending on the make and model of the motorcycle, as well as the ambient temperature. In extreme dyno testing designed to create engine heat, we’ve seen cylinder temperatures as high as 383°F (195°C) in an air-cooled Harley-Davidson* V-Twin engine. That means the oil breaks down more than 16 times faster than at normal operating temperature!
AMSOIL Synthetic Motorcycle Oil uses high-quality synthetic base oils that naturally resist thinning and breakdown due to extreme heat and mechanical engine activity. As a result, it forms a thick, strong lubricating film on engine components despite the intense heat motorcycle engines can generate. It also features a robust additive package designed to protect motorcycle engines and transmissions from wear, while improving clutch feel.
Riders who use AMSOIL Synthetic Motorcycle Oil gain peace of mind and protection from the risk of losing oil-pressure and potentially causing severe engine damage, so they can enjoy riding harder, faster and farther all summer long!
Not sure which AMSOIL products are right for your motorcycle? Find the right AMSOIL Synthetic Motorcycle Oil, Oil Change Kits and other products for your V-twin, dirt bike, race, street, touring, adventure or dual-sport motorcycle by using our convenient Motorcycle Lookup Guide.
V-Twin Oil Change Kits
Whether you ride a vintage Harley or have a newer Milwaukee-Eight* engine, AMSOIL V-Twin Oil Change Kits include everything you need to get the job done.
Not sure which AMSOIL V-Twin products are right for your bike? Check out our convenient motorcycle lookup guide to quickly find exactly what you need.
