20w-50 indicates Synthetic-oil
SAE 50 is a single weight oil that is 50 weight when cold or hot. SAE 20w50 is a multi-grade oil. When cold it flows as a 20 weight oil and therefore flows much easier. At full operating temperature it flows as a 50 weight oil. The W stands for winter.
SAE 20w50 synthetic.
if using your bike in the summer use sae 20w50 but for starts below 50 degrees use sae 10w40
SAE 20w50 100% synthetic oil.
No, use exactly what Cummins recommends and nothing else.
NO no, you will ruine trans.
Check out this URL: http://www.upmpg.com/tech_articles/motoroil_viscosity/ I believe your question will be answered there.
Jic is a 37° Flared Fitting sae is a 45° Flared Fitting
The recommended viscosity grade for use in all temperatures is SAE 20W50 for your 2008 Heritage
They will mix together, but only use it in an engine if it is an approved combination of oil according to the manufacturer.
According to the Kawasaki site you should use SE class SAE 10W40, 10W50, 20W40 or 20W50 oil for the engine. You use SAE 10W oil for the front fork.
SAE 10W could be using in larger of range temperature, so SAE with W character also means suitable for winter season as well as tropical season or ambient temperature. this SAE 10W also means multi grade oil. thanks