For weather temperatures between 10 and 100 degrees Fahrenheit, SAE 10W30 motor oil is recommended for Yamaha V-Star 650 motorcycles. For temperatures between 40 and 120 degrees Fahrenheit, the owner's manual recommends SAE 20W40 motor oil. Change the oil after the first 600 miles or one month of operation and then every 4,000 miles or six months thereafter, and replace oil filter elements every year after the initial oil change.
The difference between the two oils involves viscosity, thickness and seasonal driving. SAE 10W30 is for colder months and works for lower temperatures. SAE 20W40 is designed for warmer months and higher temperatures. SAE 20W40 was introduced in 1974 as a multigrade oil with low viscosity designed to prevent oil rings from sticking in heavy-duty engines. SAE 10W30 oil has a low viscosity, even though newer oils, such as 5W30, may show better fuel efficiency in tests conducted in 2013.
The 2014 Yamaha V-Star 650 Classic features a fuel efficiency of 59 miles to the gallon, a displacement of 40 cubic inches, a five-speed transmission and a 3.5-gallon fuel tank. The wheel base is 64 inches for a low, stable ride. The torque of the engine is designed for optimum speeds between 30 and 75 mph, with chrome all over the motorcycle's frame and parts.