300R oil type?

[stan r]

I have a Mercury 300R. I’m a little confused from the Owners Manual which oil to use 10W-30 or 25W-40. Thought it would be a excellent idea to ask the experts here on Scream and Fly. Maybe even get a better alternative suggestion. Thank you ahead for the help!

[JPEROG]

Run the 25-50 Mercury synthetic Stan. They have done serious durability testing and the results are amazing when using that oil.

Joe

[obrien]

In the new v8s and v6s mercury prefers the 10w-30. You can use the 25-40 but the 10-30 is what they ship the engines with

[stan r]

Joe it’s been quite awhile but you helped me with props in the past. Thank you for the help again! You are one of the best guys on here along with Randy who sold me the boat and motor. Always willing to help guys, especially some of us without the big wallets. What a great website, how lucky we are to have it!

[Jim Speros]

Run the 25-50 Mercury synthetic Stan. They have done serious durability testing and the results are amazing when using that oil.

Joe

Thanks Joe.

I will run the the 10-30 for the first 10 or so hours. I will be running the heavier oil like you in the summer and probably the 25-40 in the winter. I base my decisions on temperature range I live in. The water is 80 to near 90 and air often 100 or more in summer. The water only cools to 70's in winter. Plus I generally run hard.

[Chaz]

Can someone give me the address to Mercury's oil refinery. I'd like to Google Earth it .. you know, to see what it looks like from the air and ground level ...

[stan r]

Thanks for the response O’Brien, Jim, and Joe!

[JPEROG]

Can someone give me the address to Mercury's oil refinery. I'd like to Google Earth it .. you know, to see what it looks like from the air and ground level ...

Did you get a 4 stoke new motor like the rest of us in the discussion? Hope you make it for the shootout in August "lots of shrimpheads and porkchops for you to sample". All Mercury racing stern drive motors and 450s come with the 25-50. It is a mercury blend made and labeled to their specs with added wear and corrosion additives. I was privileged to hear the results of the oil sample analysis after a 300R was run for 100 hours on the dyno at WOT. My 300Rs were drained and changed to this before they were ever started (just my 2 cents) after talking to the people that know.

Joe

[Jim Speros]

Interesting... Kinda new school of thought away from break in with lighter oil or with non synthetic.

I just went to check what I have. Quicksilver High Performance 25-50 synthetic blend. Is the oil marked Mercury racing the same?

[JPEROG]

Yes

Joe

[Capt.Insane-o]

Can someone give me the address to Mercury's oil refinery. I'd like to Google Earth it .. you know, to see what it looks like from the air and ground level ...

It's who Mercury hasn't pissed off.... but more than likely Warren Oil Distb. If your a casual user the 10w-30 is fine. I hate everything I drive so I will suffer the parasitic loss of syrup 25w-40. What ever the owners manual has for jiffy lube intervals cut it in half.

[Chaz]

Did you get a 4 stoke new motor like the rest of us in the discussion? Hope you make it for the shootout in August "lots of shrimpheads and porkchops for you to sample". All Mercury racing stern drive motors and 450s come with the 25-50. It is a mercury blend made and labeled to their specs with added wear and corrosion additives. I was privileged to hear the results of the oil sample analysis after a 300R was run for 100 hours on the dyno at WOT. My 300Rs were drained and changed to this before they were ever started (just my 2 cents) after talking to the people that know.

Joe

Ahhh, J.P. , all I asked for was an address.

Why is it .. you ask some folks what time it is .. and they wanna take 5 minutes to tell ya how they "think" the Swiss build watch's ..

The Capt. states :

It's who Mercury hasn't pissed off....

Well Capt. that doesn't go along with the narrative of snake oil specially blended with 11 herbs and spices ... by Mercury .. err .. just for Mercury ... LMAO

https://warrendistribution.com/

Private label .. Same bulk **** special Mercury price mark-up ...

Chaz = rememberin, Mobil-1 was the first and best synthetic multi-viscosity oil, hypoid and bearing grease. Still must be if the put it in the C-8 Corvettes .. and recommend it's use after the sale ..

Nope .. I want me some of that Chev-o-lay oil ...

[JPEROG]

They have run mobil-1 in comparison. When you are selling 1350, 1550, and 1750 at the price that they are knowing that they get run at 7000 rpm for up to 30 min. intervals and they are standing behind the warranty, they want the best "snake oil" possible. Let me know when a corvette is ever held at redline like a boat motor (twenty min. or more for several outings over its life span) and lives its life breathing saltair and or marine environment moisture levels every-time it gets run then we are talking apples to apples. Until then its not a comparison.

Again, thanks for your concern about us "porkchop" owners that are trying to catch up to you on the runs.

https://www.ebay.com/itm/26451204333...QAAOSwoBFdtKkU

-and the best part is that it no longer gets added to our lake water like the two stroke oil but its contained for continued use and proper disposal every 100 hours of run time (think of how many years that would be with your motors running). I agree with Capt. 50 hours is when mine gets changed and gear lube is every 20.

Joe

[DangerNewb]

Run the 25-50 Mercury synthetic Stan. They have done serious durability testing and the results are amazing when using that oil.

Joe

Just looking back at my owners manual. Doesn't even mention 25-50. Shows 10-30 as appropriate for temps up to 120 degrees F. Mentions 25-40 as an alternative but no mentioend of 25-50.. Also says specifically to not use full synthetic. I've never seen my motors over 150 degrees according to my garmin. Do you have any reference material that recommends the 25-50?

[Jim Speros]

I'm curious to see what he shares to read. Based upon my start up temps in Texas, my persistence in allowing my stuff to warm up and cool, and finally how hard I like to run the 25 50 is a no brainer. I will run the first short interval with the oil in it though.