what oil to run in motor
#21
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Location: Michigan
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I run straight 40w. I remember Bob Teague recommending straight weight oils in a tech column a few years back. IIRC, it had something to do with multi-grades not handling moisture as well as straight grades, and who starts there engines and just takes off with them cold anyway?
#22
Geronimo36
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15/40 is fine and I don't remember correctly but that' could be what's recommended. Mercury oil is a 15/40. Boat engines need a higher viscosity rating than car engines for a few different reasons. I'd run a 15/40 or even a straight 40W if you boat in warm weather. I run straight 50W in my 800's.
#23
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You wonder why there is so much confusion on oils.
A 25w40 IS A MULTI-VISCOSITY!!!!!!!
Who told you that an XX w XX oil IS NOT MULTI-VISCOSITY?
It has no bearing on the viscosity whether the oil is blended or not.
And the oils you suggested...guess what, ALL MULTI-VISCOSITY.
Ken
A 25w40 IS A MULTI-VISCOSITY!!!!!!!
Who told you that an XX w XX oil IS NOT MULTI-VISCOSITY?
It has no bearing on the viscosity whether the oil is blended or not.
And the oils you suggested...guess what, ALL MULTI-VISCOSITY.
Ken
Edit: here is the latest description of the oil. Different than what I remember from the past. Merc states it is a multi-viscosity. I will look through the old oil thread to see if I can find information to back what I believe Merc used to market the oil as.
http://www.mercurymarine.com/parts-a...ercruiser-oil/
Last edited by Knot 4 Me; 08-04-2010 at 08:59 AM. Reason: more info...
#24
Geronimo36
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Mobil 1 is treated as a multi-visc but in reality it's not blended as a multi-visc oil like most other brands. It's classified with that rating because it has the ability to flow in cold weather like a 15W but also has the ability to protect at high temp/load like a 50W.
That's my understanding at least.
That's my understanding at least.
#25
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I was just stating what I run and one of the reasons why I do what I do. My 454 mag has been running on straight wt oil for 21 years, and I highly doubt that multi-grade oil would make it last any longer. Multi-grade oils are for people that start their engines and are too busy to warm them up before running them. Yes, multi-grade oils are newer technology, but not necessarily better technology, they are for different applications. Brad Penn and Royal Purple make and sell SYNTHETIC STRAIGHT WT oils.
#26
Registered
You wonder why there is so much confusion on oils.
A 25w40 IS A MULTI-VISCOSITY!!!!!!!
Who told you that an XX w XX oil IS NOT MULTI-VISCOSITY?
It has no bearing on the viscosity whether the oil is blended or not.
And the oils you suggested...guess what, ALL MULTI-VISCOSITY.
Ken
A 25w40 IS A MULTI-VISCOSITY!!!!!!!
Who told you that an XX w XX oil IS NOT MULTI-VISCOSITY?
It has no bearing on the viscosity whether the oil is blended or not.
And the oils you suggested...guess what, ALL MULTI-VISCOSITY.
Ken
http://www.offshoreonly.com/forums/g...cation-72.html
#27
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If an oil's flow rate meets or performs "like" a 20w oil and when elevated to the proper test temp, meets or performs "like" an SAE 50 that particular is a multi-viscosity oil period.
It does not make any difference if the oil was blended with straight cut base stocks or with a polymer.
If thereis a "w" in the descriptor of the viscosity, I am sorry to say, it is a multi viscosity.
Knot 4 me sorry for jumping in your S***, but just because Mercury says something doesn't mean it is correct, espically with something they don't even manufacture.
Ken
It does not make any difference if the oil was blended with straight cut base stocks or with a polymer.
If thereis a "w" in the descriptor of the viscosity, I am sorry to say, it is a multi viscosity.
Knot 4 me sorry for jumping in your S***, but just because Mercury says something doesn't mean it is correct, espically with something they don't even manufacture.
Ken
#28
Registered
If an oil's flow rate meets or performs "like" a 20w oil and when elevated to the proper test temp, meets or performs "like" an SAE 50 that particular is a multi-viscosity oil period.
It does not make any difference if the oil was blended with straight cut base stocks or with a polymer.
If thereis a "w" in the descriptor of the viscosity, I am sorry to say, it is a multi viscosity.
Knot 4 me sorry for jumping in your S***, but just because Mercury says something doesn't mean it is correct, espically with something they don't even manufacture.
Ken
It does not make any difference if the oil was blended with straight cut base stocks or with a polymer.
If thereis a "w" in the descriptor of the viscosity, I am sorry to say, it is a multi viscosity.
Knot 4 me sorry for jumping in your S***, but just because Mercury says something doesn't mean it is correct, espically with something they don't even manufacture.
Ken
#29
Geronimo36
Gold Member
If an oil's flow rate meets or performs "like" a 20w oil and when elevated to the proper test temp, meets or performs "like" an SAE 50 that particular is a multi-viscosity oil period.
It does not make any difference if the oil was blended with straight cut base stocks or with a polymer.
If thereis a "w" in the descriptor of the viscosity, I am sorry to say, it is a multi viscosity.
Knot 4 me sorry for jumping in your S***, but just because Mercury says something doesn't mean it is correct, espically with something they don't even manufacture.
Ken
It does not make any difference if the oil was blended with straight cut base stocks or with a polymer.
If thereis a "w" in the descriptor of the viscosity, I am sorry to say, it is a multi viscosity.
Knot 4 me sorry for jumping in your S***, but just because Mercury says something doesn't mean it is correct, espically with something they don't even manufacture.
Ken
That's the key differentiator in my mind.
Here's an informative article here for the others concerned about using a multi-visc. vs. straight weight; http://www.blackstone-labs.com/oil-viscosity.php
Last edited by Panther; 08-06-2010 at 08:06 AM.