No, Rotella T 15W40 is approved for both gasoline and diesel engines. The "C" spec is diesel, "S" is gasoline. See the red/yellow box on the right of this link: http://www.shell.com/rotella/products/tpl-pro.htmlClarkTheShark wrote:I'm confused... The "Rotella T 15w40" I've been buying is wrong?
The perfect oil for your Spider would be one that is blended using modern chemistry to perform in a flat-tappet gasoline engine, without emissions or economy concerns. There are specialty oils available (mostly online) that are blended for engines such as ours, if you are fanatical. Everything available in the oil aisle of your local store is a compromise in your Spider engine, but as I and others have said, anything with an "S" approval and the correct viscosity will be OK. You could Search the 39,000 posts on this tab alone, and not find a single-oil-related engine failure among them.