Synthetic oil for my outboard

[foxer]

Its a Suzuki DF140 (Four stroke). Manual says to use 10w-40. Since it sees most of its life at mid to upper rpms I was thinking of switching to synthetic. Havent found any 10w-40 except for Amsoil. Any others?

 

[Gene K]

If you want to run "10W-40" in a Synthetic your other two choices that are relatively common are Castrol Syntec (Group III) and Redline (Group IV/V).

Most Synthetics are 0W or 5W-40 instead of 10W-40.

 

[Steve S]

Redline makes a 10w/40. Give it a try and let us know how it works.

 

[Craig]

Been using the 0w-40 Amsoil in my 15hp Yamaha for 3-4 years
without problems. They have a new 10W-40 Marine 4 stroke oil
which is probably close the their regular pao 10W-40 but with
a good dose of anti oxidation additives added.
Craig

 

[TeeDub]

The Amsoil 10w-40 Marine oil should last you a whole season of boating, even if you're putting lots of hours on the boat. The stuff is expensive, but I don't think you'll find anything to outperform it.

I like the specs of these new Marine oils so much, I'm currently using the API/SL rated, Amsoil 10w-30 Marine oil in my new Subaru Outback, with the 2.5L motor.

 

[Turk]

Howdy,

I have the same motor also run it like you do!

The last 2 years I've used Amsoil e4-Stro e Marine 10-40 and the engine Loves it. It just sings with it in.

I also use the Amsoil in the Lower unit.

I highly recommend the Amsoil

 

[Steelhead]

try the Rotella T Synthetic 5w40 HDEO, reasonable price and available everywhere.
common commercial marine diesel oil which is extreme service

 

[Steelhead]

Quote:

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try the Rotella T Synthetic 5w40 HDEO, reasonable price and available everywhere.
common commercial marine diesel oil which is extreme service

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the 5w helps with cold winter spring salmon trolling starts and reduces cold start wear

 

[Turk]

It looks like the absolute best oil for the 4-stroke outboards is Amsoil. The additive pack is specifically for what type of hard use and anti-oxidation. Even with 10% Water in the oil, it still exceeds what the engine requires.

Pick up Amsoil 4-Stroke Marine Oil, you will be very happy with it and your engine will thank you for it.

Get the Marine Lower Unit oil also, it far exceeds any other type of Lower Unit oil.

 

[bmwtechguy]

Ok, I'll buy the 10% water for the lower unit gear oil, but not for the engine oil. Are you serious about that claim, or is it a mistake and you meant the gear oil? If you have 10% water in your engine oil or even 5%, you best find out how it got there and fix it, then change your oil and filter, flush the engine and then change it again before running it under load!

 

[Turk]

Yes, it is the lower unit. I heard that claim from Amsoil with their testing.

Anyone going with Amsoil on their Outboard, let us know!