Originally Posted By: 02s4audi
So 20w50 is Harleys preferred option in these but others could be used? I live in ny and the bike will be driven up until it's just too cold or snow flies
Yes 20w-50 is the preferred viscosity even running a diesel spec oil. It can be difficult to find 20w-50 diesel oil, most will be 15w-40 at discount stores.
Valvoline 20w-50 and Mobil 1 20w-50 Motorcycle oil can usually be found at Wally World. Both seem to give good UOA results in Harleys.
Another thing to keep in mind is riding when the air temp is less than 60 F. The drian intervals are reduced from 5000 miles to 1500 miles.
This is from a 2013 Sportster owners manual-
Change engine oil often in colder climates. If motorcycle is frequently used for trips less than 15 mi 24 km , in ambient temperatures below 60 °F 16 °C , reduce oil change intervals to 1500 mi 2400 km .
NOTE:
The further below freezing the temperature drops, the shorter the oil change interval should be.
Water vapor is a normal by-product of combustion in any engine. During cold weather operation, some water vapor condenses to liquid form on the cool metal surfaces inside the engine. In freezing weather this water will become slush or ice. Over time, accumulated slush or ice may block the oil lines and cause engine damage.
If the engine is run frequently and allowed to thoroughly warm up, most of this water will become vapor again and will be blown out through the crankcase breather.
If the engine is not run frequently and not allowed to thoroughly warm up, this water will accumulate, mix with the engine oil and form a sludge that is harmful to the engine.