Just bought a Nitro Z-7 with a Mercury 150 Optimax. The person I bought from gave me a gallon jug of Mercury direct injection oil. (Didn't know it even existed). My question is I've always used Mercury Quick silver oil. What if any difference is there, and should I be using the direct injection oil?? Thanks!

No difference between Mercury and Quicksliver, and yes, you should be using the DFI oil, along with Quikleen at the rated amount in every tank.

Gman

What GAMBLINMAN said

Follow your outboard manual directions....if needed, find and down load on computer for future reference.

My 2014 Mercury 250 Pro XS is recommended to use the DFI oil. I know folks will say you can get away with using premium plus or a myriad of other oils, but that is what Mercury says to run in it. Considering what it costs to rebuild one, the little extra I spend on oil is worth it to me. I do a lot of idling using my graph and have never had an issue with fouling plugs or any other issue with DFI oil so I'm gonna keep using it. It is a pure synthetic so it is going to be higher than blended or pure fossil oil. I do run Quickleen and Quickare in every tank also. Do your due diligence and use what you think will give you the best results for your money.