synthetic oil mix

Can I mix Mercury synthetic 2 stroke oil with Mercury regular 2 stroke oil?
Thanks

Yes, as long as both oils carry the rating required by your particular engine.

Performance characteristics like smoke may vary from what you see with your usual oil.

Just curious as to why you are doing this? Just using up old oil?

Grouse

TheFamousGrouse wrote:

Just curious as to why you are doing this? Just using up old oil?

My guess was topping off the tank with new synthetic oil.

Here is what I was told by a Merc mechanic years ago.

Mix the 2 oils in a jar and let sit for at least 24 hours. If the mix does not gel, good to go.

In any case, it is best to run down the existing oil to low, then add in the new oil to the tank.

-J.

I bought a gallon from a friend who sold his boat, didn’t notice it was synthetic til I got home.

You should be fine, I mixed all kinds of oil and weights to get rid of my stash mis quarts I had sitting around, with no problems.

What Merc are you putting them in? If it’s an Optimax, then NO you cannot do that. A regular 2 stroke should be fine. I would use one up as much as possible, then refill your reservoir with the synthetic.

blackbay wrote:

What Merc are you putting them in? If it’s an Optimax, then NO you cannot do that. A regular 2 stroke should be fine. I would use one up as much as possible, then refill your reservoir with the synthetic.

I run strictly AMSOIL Synthetic HP oil in my optimax. I too would hesitate to mix them for the Opti. At the very least, I’d run the tank to the low oil reservoir indicator and then add it.

Jon Jordan wrote:

Here is what I was told by a Merc mechanic years ago.

Mix the 2 oils in a jar and let sit for at least 24 hours. If the mix does not gel, good to go.

In any case, it is best to run down the existing oil to low, then add in the new oil to the tank.

-J.

^^^^^^ true.
why?? additive clash which was a huge problem years ago.

blackbay wrote:

What Merc are you putting them in? If it’s an Optimax, then NO you cannot do that. A regular 2 stroke should be fine. I would use one up as much as possible, then refill your reservoir with the synthetic.

^^^ true,if it requires DFI oil you do not want to mix oils,plug and port fouling is a big issue on these motors ( DFI engines )