Harley-Davidson Shovelhead engine
Although Harley riders pay a premium for their motorcycles, they may try to find ways to cut costs elsewhere. With the price of Harley-Davidson branded oil being so much more expensive than automotive oil, Harley riders might wonder if the two are interchangeable.
There are really two comparisons here: Harley-branded oil vs. non-Harley oil and motorcycle-specific oil vs. automotive oil. There is no reason to use only Harley-Davidson branded oil if you choose not to. Not only can you find other oils that work as well or better, but using another brand oil will not void your warranty.
Some brands of oils can be used in both cars and motorcycles and some cannot. If you’re in a pinch and need to add some oil where only automotive oil is available, then use it. Just be sure that you don’t mix synthetic with petroleum oil.
Before changing the type and brand of oil you use in your Harley, you should do a lot of research. Some riders are adamant that the old petroleum oils are best, while others insist on synthetics. There are also different manufacturers of synthetics. You’ve invested a lot in your motorcycle; you should make an informed decision.