check this topic out
http://www.charlestonfishing.com/for...TOPIC_ID=57068
I have allways liked shell rotella oil, there have been some articles in some magazines about it recently, and I know some highly regarded engine builders that use it regardless of what the sponser stickers say. Most of the big rigs you seee running down the highway are using it, and gettin close to 1,000,000 miles on an engine. I called shell to see if rotella was ok for a four stroke outboard, they were very nice and pleasant to deal with, didn't have to a machine or prompt the who;le time. They said Rotella hasn't been tested for marine four cycle engine, not that it wasn't ok, just it hasn't been tested, of course he said their other division(Penzoil) had a specific four stroke oil for outboards. I haven't tried rotella yet, but after talking to these guys I wouldn't feel bad about using Penzoil. Give them a call(got the # of their website), they are veruy helpful and will try their best to answer your questions