RE: DLE 55 oil slection?
I use Redline 50:1 and have not bothered to research for better oil. My auto repair shop uses the same brand oil for my Benz and seems to work well for years.
It's much more important to properly tune your motor than to worry about oil brands.
Check your plug after every gallon of use to make sure you're not running too rich or lean.
That's my 2 cents.