No synthetic in Nissan/Tohatsu OB?

[thunderfog]

From the website:

"Use of synthetic oil is not recommended in 4-stroke outboard engines. Outboards use raw water cooling systems and using synthetic oil may prevent the engine from reaching sufficient operating temperature."

Any thoughts on this? I guess I'd go PYB...

 

[Bluestream]

Makes no senses at all...

 

[RF Overlord]

First time I've heard that, but then again the last outboard I worked on was a 1969 40HP Johnson...

 

[Doc_Stressor]

The logic is that since synthetic base stocks have a higher heat capacity than conventional stocks, they carry heat away from engine parts more efficiently. Heat is necessary for a proper break in.

That's the same reason some manufacturers recommend against synthetic oil during break in of diesel engines.

4-stroke outboards often have a problem with "making oil" or fuel dilution if they aren't broken in properly. Particularly if they are used for trolling. Outboards need as much heat as possible to flash off fuel and moisture from the oil. Anything that causes the engine to run cooler is not usually a good thing.

 

[thunderfog]

Originally Posted By: Doc_Stressor
The logic is that since synthetic base stocks have a higher heat capacity than conventional stocks, they carry heat away from engine parts more efficiently. Heat is necessary for a proper break in.

That's the same reason some manufacturers recommend against synthetic oil during break in of diesel engines.

4-stroke outboards often have a problem with "making oil" or fuel dilution if they aren't broken in properly. Particularly if they are used for trolling. Outboards need as much heat as possible to flash off fuel and moisture from the oil. Anything that causes the engine to run cooler is not usually a good thing.


Cool to know. Will follow the rules, although I planned to anyways...

 

[Bluestream]

Originally Posted By: Doc_Stressor
The logic is that since synthetic base stocks have a higher heat capacity than conventional stocks, they carry heat away from engine parts more efficiently. Heat is necessary for a proper break in.

That's the same reason some manufacturers recommend against synthetic oil during break in of diesel engines.

4-stroke outboards often have a problem with "making oil" or fuel dilution if they aren't broken in properly. Particularly if they are used for trolling. Outboards need as much heat as possible to flash off fuel and moisture from the oil. Anything that causes the engine to run cooler is not usually a good thing.


AN outboard has an ample supply of cooling water, and most are thermostat controlled.. The few degrees of temperature reduction from synthetic oil would be inconsequential.

Other manufactures don't have this restriction, so it makes one wounder.

 

[edhackett]

Originally Posted By: Doc_Stressor
The logic is that since synthetic base stocks have a higher heat capacity than conventional stocks, they carry heat away from engine parts more efficiently. Heat is necessary for a proper break in.


The problem with that "logic" is that synthetic oils have a lower heat capacity(specific heat) than mineral oils.

Specific heat of new oils at 100C :

Mineral 3.101
Mineral without additives 2.867
Synethetic 2.944
Semi-Synthetic 2.984

http://docsdrive.com/pdfs/medwelljournals/jeasci/2006/495-499.pdf

Google will return other papers with corroborating results.

Ed

 

[Tuffy1760]

would the use of syn oil void the warranty??

 

[sHERM]

Wow, I was using Amsoil marine oil in my Mercury until I sold it last month ? Had no issues, but this is interesting to hear?

 

[compressignite]

This is Bushwa!
FW-c rated Fully Synthetic 4-Stroke oils ARE the best option !

Howeveah!
Some of Marine Engine Assemblers
(Aint' ALL actual manufacturers)
Haven't YET joined the 19th Century
as far as Machining and Q.C. Tolerance of Cylinder Wall/Ring Lands/Rings are concerned.

"Break in" with Non-Synthetic Lube is still the best way.
As always "Break In" , When properly executed involves HOURS of "Riding The Throttle"
UP AND DOWN to make sure NO RPM range is "Set In" to the Rings!!!

 

[compressignite]

If you're using FW-c rated Oil at the proper Viscosity

the Manufacturer (Engine)HAS No WHERE TO Go! Period!

BUT,DO NOT PAY ANY ATTENTION TO "EXTENDED" Oil Change scenarios!
Change your oil as directed by the Manufacturer!

It's been proven,legally,that the use of Synthetics Can't void Warranties.

 

[ironman_gq]

I follow a pretty effective routine for breaking in new engines. First 20-30 minutes, no idling just up and down between 1500-2500rpm. Let it cool, change the oil if you want to. The rest of the break in I run it like I stole it and keep an eye on temps, if things start to warm up I back off and let it cool down.

Never had an issue with glazed cylinders or ring seating, or anything else for that matter. Things tend to run a little hotter till everything is completely seated but if your going to have a major mechanical issue they generally become known during the first half hour.

After the break in I like to switch over to whatever oil I plan on using for the life of the vehicle (for most things I like a short OCI for the first one, there tends to be a lot of trash floating around in the castings that finds its way out after a few heat cycles)

 

[fisher83]

My new Yamaha 2.5 hp has similar wording in the owner's manual recommending against the use of synthetic. I thought it was a little strange too.

 

[cavitating]

Hard to believe when Yamaha sells synthetic outboard oils.

https://www.yamahapartsandaccessories.co...e+Oils&d=30

 

[fisher83]

You are correct. I double checked my owner's manual and it does not say I can't use synthetic.

 

[CT8]

I would use a HDEO oil.

 

[CT8]

I wouldn't worry about the syn VS petro oil use. A HDEO with the recommended viscosity and that will be all you need. HDEO is used in half million dollar engines .If Syn was so much better do you think the operators of such engines use only syn oil?