Bass Fishing HomeBass Fishing Forums

Go Back   BassFishin.Com Forums > Serious Conversation Only > Bass Boats, Trailers & Setups

Reply
 
Thread Tools Rating: Thread Rating: 5 votes, 5.00 average. Display Modes
Old 03-30-14, 09:27 PM   #1
MO_CPA
BassFishin.Com Active Member
 
Join Date: Jun 2011
Location: Ozark, Missouri
Posts: 361
Default 10w-30 vs 25w-40

Hi all,

I have a 2011 60hp Four Stroke Mercury outboard. I dug into my owner's manual and I noticed that it recommends 10W-30 for colder climates (40 degrees F or less) or 25-40 for warmer climates. Living in MO, I run the boat in some hot weather in the summer and I have been using 10w-30 Four Stroke Quicksilver this whole time!

A couple questions:

1. For a non-high performance engine such as mine, does it matter if you use 10W-30 vs 25W-40?
2. If it does matter, do you think I could have messed up the engine in the two years that I have ran 10W-30?

I appreciate your thoughts and input.
__________________
Whatever you allow is what will continue.
MO_CPA is offline   Reply With Quote
Old 03-30-14, 10:48 PM   #2
nobass
BassFishin.Com Super Veteran
 
Join Date: Jul 2003
Location: clarksville, tn,
Posts: 1,690
Default

I would just use the 25 40 in the summer and if you going to do a hard winter fishing up the. 10. 30
__________________
the only easy day was yesterday
nobass is offline   Reply With Quote
Old 03-30-14, 11:31 PM   #3
mikechell
BassFishin.Com Active Member
 
Join Date: Apr 2011
Posts: 464
Default

10W ... is the pour point viscosity of the oil. This means that it flows thinner as it gets hotter and acts like a straight weight 10 throughout the temperature ranges. The 30 is the protection factor, based on the long strand polymers that "hold" the oil in place at the microscopic layer of protection between moving parts. These polymers only open up at higher temperatures, and only affect the oil at those boundary layers. (so the oil still runs thinner through large openings like drain holes)
You do NOT want to run the 25W oil during winter months, it's too thick to flow into the boundary areas when cold. But there is probably no reason you couldn't run the 10W30 during summer, except that the manufacturer tells you not to. I teach guys how to work on Honda outboards, and there is no summer/winter difference recommended for those engines. Air temp means so little in a liquid cooled engine, and outboards are particularly cool running, because of the open cooling system.
I do NOT think you've damaged your engine. I firmly believe 10W30 is plenty of protection for all lower 48 states ... even here in Florida.
Two final points:
1. Does it state what "warmer climates" means in temperature?
2. If it's under warranty, follow manufacturer's instructions at all times.
mikechell is offline   Reply With Quote
Old 03-31-14, 12:38 AM   #4
MO_CPA
BassFishin.Com Active Member
 
Join Date: Jun 2011
Location: Ozark, Missouri
Posts: 361
Default

Great reaponses!

>40 degrees Fahrenheit requires 25w 40 per the manual. That is why I was concerned.
__________________
Whatever you allow is what will continue.
MO_CPA is offline   Reply With Quote
Old 03-31-14, 01:32 PM   #5
mikechell
BassFishin.Com Active Member
 
Join Date: Apr 2011
Posts: 464
Default

Quote:
Originally Posted by MO_CPA View Post
Great reaponses!

>40 degrees Fahrenheit requires 25w 40 per the manual. That is why I was concerned.
Wow !!! +40 degree F is pretty much everywhere in the country during the summer. This would be considered the "normal" temperature zone. I take back what I said earlier ... run the 25W40 during the Summer, Fall and Spring. There's a huge pour point viscosity difference between 10 and 25 weight fluid. I will reiterate the warranty advise. If the weather dips below 40F, don't worry about the changing from 25W40. If it stays below, then you'll want to run the 10W30 for the thinner cold temp flow.

I am going to have to research this.

Last edited by mikechell; 03-31-14 at 01:39 PM.
mikechell is offline   Reply With Quote
Old 03-31-14, 05:27 PM   #6
MO_CPA
BassFishin.Com Active Member
 
Join Date: Jun 2011
Location: Ozark, Missouri
Posts: 361
Default

I know @mikechell. I was surprised myself. I picked up a gallon of the Quicksilver 25w-40 4 stroke at Wal-Mart today. I will use it from now on.

Crossing my fingers for no damage to the motor. Surely I would have sounded an alarm or something if it was overheating or having oil issues?

The general internet concensus is that it is an over precaution by Merc that far exceeds what other motors require. Oh well, better safe than sorry if I suppose.
__________________
Whatever you allow is what will continue.
MO_CPA is offline   Reply With Quote
Old 07-28-14, 07:56 AM   #7
Thornback
BassFishin.Com Active Member
 
Join Date: Aug 2012
Location: Ocala, Florida
Posts: 156
Default

I have the same engine on my 17.5' Bass Tracker and have been running 10W-30 Quicksilver for 9 years (200 engine hours). I live in Florida -- 95 degrees in summer and sometimes 28 degrees in winter. The engine has never had a problem, doesn't burn oil, never been in a repair shop.
Thornback is offline   Reply With Quote
Old 07-29-14, 06:26 PM   #8
mikechell
BassFishin.Com Active Member
 
Join Date: Apr 2011
Posts: 464
Default

I am going to chime in here again, just because I believe my research. The operating temperature of an engine doesn't vary much between summer and winter times. If your engine runs at 170 degrees in the heat of summer, it will run at 170 in the cold of winter, if air temp was all we need think about. The whole "thicker oil in hotter climates" thing is, in my opinion, baloney.
Now, water temperature CAN effect the engine temperatures, if your system doesn't use a thermostat. (Small displacement engines are sometimes designed without thermostats)
If you have, or know somebody who has, an infrared temp gun, then do the research yourself. Point that gun at the valve cover as soon as you take the lid off of a hot engine. Do this during different times of the year. If you notice huge differences, then perhaps you should change the viscosity of the oil with major temp changes. If you don't, then run the thinnest oil recommended by the manufacturer. Thinner oil means less hydraulic drag, hence, more power from your engine.
mikechell is offline   Reply With Quote
Old 07-29-14, 08:53 PM   #9
Thornback
BassFishin.Com Active Member
 
Join Date: Aug 2012
Location: Ocala, Florida
Posts: 156
Default

Quote:
Originally Posted by mikechell View Post
Thinner oil means less hydraulic drag, hence, more power from your engine.
Better lubrication, too. You can also put your hand into the pee stream to confirm temp. The circulating water and thermostat on most engines will keep the temp fairly even in most climes. Just like an automobile.
Thornback is offline   Reply With Quote
Reply

Disclosure / Disclaimer
Before acting on the content posted, you should know that BassFishin.Com may benefit financially and otherwise from content, advertising, links or otherwise from anything you click on, read, or look at on our website. Click here to read our Disclosure Policy and Disclaimer.


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:36 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
2013 BassFishin.Com LLC