I just rebuilt a Craftsman Chipper/shredder with a 5 HP B&S Industrial Motor. It’s states specifically in the owner’s manual to use 30w oil. It also states that using blended oil is acceptable, but will cause oil loss.
I researched this further and I found out that the blended oils, 10w30 or 40 or whatever, add polymers to bond the varied oil weights and the polymers can break down.
Bottom line, a single weight oil, chosen for conditions, is always better. We lazy Americans want a single oil, and want to forget about it for too long a time. I’m reading here that some of you even want to carry just one oil for all of your vehicles!
I used Rotella 15-40 diesel oil in my ‘84 GL for years, when I lived in Austin and commuted with it during summer months. I also own an ‘03 Dodge Ram Cummins and have used that oil for 15 years. Now I live where that oil would be too thick most of the year, and I ride 12 months a year.
I never bought into the Mobil-1 perfect oil, marketing campaign. However, now I have 4 great street bikes, and I work hard to keep these running well without assistance of dealerships.
So, synthetic oil does have an advantage, when you want to just let it sit in an engine for 6 months at a time.
The last 2-3 years I have put AMSOIL 10-W40 in my GL1200. I changed my oil last time in Aug 2018. I only put about 1k miles on my GL since. I checked the oil today and it’s clean, like when I poured it in 8 months ago. The dipstick looks and smells like the oil was just changed!
I think these “improved” oils are viable for these kind of uses. When I drive a car or truck hard, lots of miles, 8-10K between changes, 2-3 times a year, I use an old-fashioned petroleum based oil and change oil often.
Keep in mind, when you own a GL1200 or other motor built 30+ years ago, there were no synthetics and they ran fine as engineered.
1984 Goldwing Standard
Last edited by JohnnyD; 04-19-2019 at 12:34 AM.