Oil change - fall or wait until spring?

tobnpr said:
Exactly what I was gonna say...
Anyone that sez to leave dirty, contaminated oil sitting in the crankcase all winter long shouldn't be turning a wrench...seriously...
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All good points. Glad I asked. He is a local guy (not my regular mechanic) that I was going to use.....maybe not.
 
From a normal mechanical background common sence says Spring (so your oil is used at it's freshest point), but!!! all the reccomendations from Mercury and everything I've read concerning boats states Fall so like everyone else has said the dirty oil isn't sitting all winter. Myself I changed mine yesterday and will do it again in the spring. but I change it myself in my little 3.0 takes about 30 minutes and 25 bucks so with that little effort and cost I believe I'll be a twice a year changer. I'm also in FL so the boat is going to go out in the winter, so my options are a bit differant.
 
sfergson727 said:
boat comes out of the water tuesday.

Back to the original point though, it's much better to have clean oil coating the engine internals than dirty, contaminated, acidic oil during the winter.
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A sad day indeed Scott - we are really spoiled in Georgia - we put our eisenglass up in mid - October and keep on boating!

But you are correct - Change oil in the fall.
 
Any harm in putting in cheap automotive oil in the fall, draining that and putting in the good stuff in the Spring?
 
"Any harm in putting in cheap automotive oil in the fall, draining that and putting in the good stuff in the Spring?"

Why not just put in the good stuff?....but you are definitely someone I would like to buy a used boat from.
 
JuliaValentine said:
Any harm in putting in cheap automotive oil in the fall, draining that and putting in the good stuff in the Spring?
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Mike,

If you don't use your boat a lot in the winter, I would think that you would want the extra anti-corrosion additives of the marine grade oil sitting in your crankcase and coating your cylinder walls all winter...unless the anti-corrosion additives are just a fraud from the oil companies...
 
The Bill Collector said:
I'm sure some big brains will get their slide rulers out and respond, but 5 hours on fresh oil is not going to hurt it too much (IMO).... I have always been told it's starting and stopping of the engine where the contaminates originate....?
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You are fine... Keep it...
 
carterchapman said:
Mike,

If you don't use your boat a lot in the winter, I would think that you would want the extra anti-corrosion additives of the marine grade oil sitting in your crankcase and coating your cylinder walls all winter...unless the anti-corrosion additives are just a fraud from the oil companies...
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Here's my thoughts on this. If you put in cheap automotive oil in, you will dilute that quart of oil/contaminants that remains in the engine and absorb the fogging oil. It all drains out in the spring (except for one quart), contaminants, fogging oil, moisture and all. The remaining quart of new automotive oil has to be better than the remaining quart of used marine oil. Then you add the good stuff in the spring and go. I REALLY doubt that an engine sitting over the winter with new automotive oil will corrode any more than one with marine oil.
 
I just put in Mobil 1 5-30 heavy duty oil for SUVs... Do most of you all use synthetic or regular oil???
 
sfergson727 said:
Even if 5w30 is rated for SUV's, I don't think it is suitable for a marine engine. I use strictly marine rated oil. I've just switched to Mercury's new full synthetic 20W40, but previously used Mercury's semi-synthetic 25W30. You could not pay me enough money to use 5w30 or 10w30 in a marine engine. If you want to use a automotive oil, at least use a straight weight 30 or 40. (unless you are just doing it to fill the crankcase over the winter, with no intentions of running with it, of course, then knock yourself out.)
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The Mobil 1 Truck and Suv oil I used exceeds all warranty requirements for GM 6094M it is ILSAC GF-4 API SM, SL/CF which is approved for diesel use, and is better than Marine Oil... I expect to see a slight improvement on my fuel economy in the spring with the lighter oil... Also, If you go to Mobil Oil website, and enter the information for the year my engines were made, and use there on-line selection guide... Their recommendations for the maximum protection is the Mobil 1 Truck and SUV 5w-30, oil I used on the boat... I know it is not called "Marine Oil", but way pay extra for a less quality oil...
 
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rcknecht said:
The Mobil 1 Truck and Suv oil I used exceeds all warranty requirements for GM 6094M it is ILSAC GF-4 API SM, SL/CF which is approved for diesel use, and is better than Marine Oil... I expect to see a slight improvement on my fuel economy in the spring with the lighter oil... Also, If you go to Mobil Oil website, and enter the information for the year my engines were made, and use there on-line selection guide... Their recommendations for the maximum protection is the Mobil 1 Truck and SUV 5w-30, oil I used on the boat... I know it is not called "Marine Oil", but way pay extra for a less quality oil...
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Interesting experiment. Diesels rev at low RPM. 454s scream at cruise. Wouldn't each have separate additives?
 
sfergson727 said:
It can meet all the requirements, which is great, but the viscosity is a problem. You need a heavier oil.
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I don't know why I would need heavier oil... :huh:The operation temperature is less than a truck with the same engine. The RPMs are higher, but a 5-30 synthetic designed for high mileage should actually improve my boat's performance, especially at high RPMs. I'll let you know know next summer if there was any noticeable change in my efficiency... :thumbsup:
 
Does the Mobile 1 have an FC-W rating? What about your engines needing Anti-foaming for sustained high RPMs and moisture control?
 
Why not use car oil in your marine engine???

The National Marine Manufacturers Association Oil Certification Committee introduced a four-stroke engine oil test and standard called the 4T certification. This specification is meant to assist boaters and manufacturers in identifying four-stroke cycle engine oils that have been specially formulated to withstand the rigors of marine engine operation. The certification was prompted by the growing influence of four-stroke engines in the marine market and their unique lubrication demands. So the simple answer is that regular road-based engine oil products don't contain rust inhibitors and won't pass the 4T certification. Lakes, waterways and the sea is a lot more aggressive an environment for an engine to operate around than on land.
Note : the NMMA have long had a similar specification for 2-stroke oils destined for marine use, called the TC-W3® certification.

BTW, shelf life of your engine oil is around 4 or 5 years. Shorter if left in harsh environments like winter and summer heat in an unheated garage or boat...
 
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As a good friend of mine said when I asked about whether or not to change the oil in my boat or lawn tractor...he said "why would you put a baby to bed with a dirty diaper?"

That said, it makes it an easy decision for me when it comes to changing the oil in my prized possessions!

There you have my $.02 worth! Good luck!
 
sfergson727 said:
It can meet all the requirements, which is great, but the viscosity is a problem. You need a heavier oil.

Here is another way to look at it. When the engine oil is cold, you are around the lower number which is rated at 5. When the engine hits it's operating temperature, the oil thickens to it's rating of 30. The one problem I can see, is that a truck/SUV operates at 210 degrees, where as your boat is around 160. Is the oil getting hot enough to reach the right viscosity to protect your engine, which by the way, endures far more stress than an SUV or Truck or Diesel auto engine? My guess is no.
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This would be a little more accurate discription of a multi-viscosity oil. What your describing is not how it works. Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot.
 
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sfergson727 said:
Funny, I don't see 5w30 listed on mercury's site, nor did I see an FC-W rating on mobile's. Don't get me wrong, I love mobile 1, and use it in all my autos. 5w30 has no business being in a boat engine though. Read the note: particularly about the part on multi-viscosity, non FC-W synthetic oils. But, if you insist you know better than Mercruiser about what oil to put in their engine than they do, knock yourself out.

What type of oil should I use? Can I use synthetic oil?

Engine Oil




To help obtain optimum engine performance and to provide maximum protection, we strongly recommend the use of the following oils listed in the order of recommendation:
  1. MerCruiser / Quicksilver Synthetic Blend, NMMA FC-W rated, 4 cycle oil.
  2. MerCruiser / Quicksilver 25W40 NMMA FC-W rated oil.
  3. A NMMA FC-W rated oil.
  4. MerCruiser / Quicksilver 4-cycle 25W40, non FC-W rated oil.
  5. A good grade straight weight detergent automotive oil per the operating chart below.
NOTE: The use of non-detergent oils, multi-viscosity oils (other than as specified), non-FC-W rated synthetic oils, low quality oils or oils that contain solid additives are specifically not recommended.
faqs_temp.gif

This crankcase oil recommendation supersedes all previously printed crankcase oil recommendations for MerCruiser gasoline engines. The reason for this change is to include the newer engine oils that are now available in the recommendation.
Older owner manuals, service manuals and other publications that are not regularly updated will not be revised to show this latest engine oil recommendation. Current owners manuals, service manuals and other service publications that receive regular updates will receive this revised recommendation the next time they are updated.

http://mercurymarine.com/serviceandwarranty/mercruiserfaqs/fueloil.php
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And in my 2007 Merc 6.2 HO manual they recommend synthetic 25W40 or one that is FC rated... like Royal Purple...
 
FW-C certification standard came out in Oct 2004, after my boat was built, so it could not have been a mercruiser requirement or recommendation for my engine... Mobil 1, may meet this standard, but they have not applied to NEMA for certification. The question on viscosity is a good one. I plan to run my boat until Dec and in early March... I wider viscosity range should help the engine when I start it at low temperatures. I am more worried about changing out my exhaust system and water pump, than the long term effects of using on FW-C certified oil in my boat... It is great to read all the comments of other OCD boaters like me... This reminds me of the complaints I got for carting my own gas from the local gas station, rather using Marina Gas...


sfergson727 said:
Funny, I don't see 5w30 listed on mercury's site, nor did I see an FC-W rating on mobile's. Don't get me wrong, I love mobile 1, and use it in all my autos. 5w30 has no business being in a boat engine though. Read the note: particularly about the part on multi-viscosity, non FC-W synthetic oils. But, if you insist you know better than Mercruiser about what oil to put in their engine than they do, knock yourself out.

What type of oil should I use? Can I use synthetic oil?

Engine Oil





To help obtain optimum engine performance and to provide maximum protection, we strongly recommend the use of the following oils listed in the order of recommendation:
  1. MerCruiser / Quicksilver Synthetic Blend, NMMA FC-W rated, 4 cycle oil.
  2. MerCruiser / Quicksilver 25W40 NMMA FC-W rated oil.
  3. A NMMA FC-W rated oil.
  4. MerCruiser / Quicksilver 4-cycle 25W40, non FC-W rated oil.
  5. A good grade straight weight detergent automotive oil per the operating chart below.
NOTE: The use of non-detergent oils, multi-viscosity oils (other than as specified), non-FC-W rated synthetic oils, low quality oils or oils that contain solid additives are specifically not recommended.
faqs_temp.gif

This crankcase oil recommendation supersedes all previously printed crankcase oil recommendations for MerCruiser gasoline engines. The reason for this change is to include the newer engine oils that are now available in the recommendation.
Older owner manuals, service manuals and other publications that are not regularly updated will not be revised to show this latest engine oil recommendation. Current owners manuals, service manuals and other service publications that receive regular updates will receive this revised recommendation the next time they are updated.

http://mercurymarine.com/serviceandwarranty/mercruiserfaqs/fueloil.php
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