5W30 is 5W30. You can add any two same weight oils together and they are chemically similar enough to be basically the same as far as the engine is concerned. You can put synthetic in too. As a matter of fact they even sell it already mixed up and call it synthetic "blend". Maybe a little better properties than pure dyno, but who knows??? Doesn't say how much is synth and how much is dyno, so probably not worth the extra $s.
