2000 Stingray 180 RX Merc 3.0
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Should work. People on here usually choose an HDEO for these marine engines though.
How about a 15-40 or 20-50
You want a HDEO oil or a diesel & gas rated oil like Rotella T.
Boats are a constant RPM run engine and prefer heavy duty oil.
The 25W40 you mention is a Merc oil I assume and is a mix of viscosities, no VMs. Its an excellent oil also.
Many people put less than 50 hours/summer on their engine and thus do not really need a synthetic.
Boats are a constant RPM run engine and prefer heavy duty oil.
The 25W40 you mention is a Merc oil I assume and is a mix of viscosities, no VMs. Its an excellent oil also.
Many people put less than 50 hours/summer on their engine and thus do not really need a synthetic.
I can't remember what the top "range" merc suggests for that particular motor, but it should be printed on the shroud that covers the air filter. It is ok to run in that range for as long as you like. If the range is 4600-5000, it is safe to run in that range until you run out of fuel...
If you look up the specs for that year and motor, you'll find a range for maximum rpm at wide open throttle. If you are exceeding that (you might be at 5000 rpm, but electric tachs aren't precise) you are under propped.
A few minutes at a time at that rpm is fine (though you should watch you water temp carefully), but as a sustained cruising rpm it's not a good idea. Try 3600ish with that older-tech motor, with the correct prop.
A few minutes at a time at that rpm is fine (though you should watch you water temp carefully), but as a sustained cruising rpm it's not a good idea. Try 3600ish with that older-tech motor, with the correct prop.
I only did it for maybe 2 minutes at a time. The Range for this motor is 4400-4800 so maybe it was only 4800rpm but the tach read 5000.
Most of the time it will not be operated like that. I just wanted to see what it could do. I def kept my eye on the water gauge.
Here's the boat getting ready to go to it's new home.
http://i24.photobucket.com/albums/c18/abmobil/336_zpsdb67cd43.jpg
Most of the time it will not be operated like that. I just wanted to see what it could do. I def kept my eye on the water gauge.
Here's the boat getting ready to go to it's new home.
http://i24.photobucket.com/albums/c18/abmobil/336_zpsdb67cd43.jpg
Couple questions. 1. What is the deal with a too high of oil pressure? When is it detrimental and why? 2. Why do the Mercury Marine engineers all recommend #1, the 25W-40 and secondly, the straight 30 wt. And since they do, why do so many posters use Rotella 15W-40 if Mercury recommends what they do?
I have asked this question in an earlier forum and never really got a straight answer on the discrepancy between what Mercury recommends and what most people are using.
I have asked this question in an earlier forum and never really got a straight answer on the discrepancy between what Mercury recommends and what most people are using.
Read the last line, seems to me it is specifically NOT recommending an oil like Rotella 15w-40. Am I wrong?
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.
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.
Use T6 5w/40 in all of our boats, and no problems or weirdness on any level. UOA's come back awesome.
Originally Posted By: philipp10
apparently you did not read my questions. I am sure a 5w-40 did just fine as its not like these motors aquire huge numbers of hours. But ancedotal evidence still does not answer the reasons of why a specific type of oil is spec'd
I actually didn't respond to your post, but if you want a breakdown,, here goes:
Originally Posted By: DoubleWasp
Quote:
There is a lot of misinformation about the right oil to use for inboard gasoline boat engines. Some of it is propagated by the engine manufacturers in order to get you to use their own brand of oil. Remember that all of these engines are just marinized automotive engines. The 4.3 Mercruiser is the same engine used in GM cars and trucks. Marinization just uses a different cooling and exhaust system and spark arrested electrical components. All of the other other components are the same as the automotive engine.
But there are differences in how a boat engine is used vs a car or truck and that is where the different oil requirements come in. Boat engines are operated at much higher rpm and load conditions than a car or truck engine. So the properties of a good marine oil that gives maximum protection under those conditions are similar to a "racing oil" used for competition rather than on the road cars or trucks. However, racing oils are not designed to hold up well under conditions of infrequent use and high humidity. The important properties for a marine oil are:
1. Sufficient viscosity to provide protection during acceleration and operation at high rpm.
2. Resistance to mechanical shear. During operation under high speed and load, the oil molecules can align with each other under extreme pressure and the viscosity can dramatically decrease.
3. Anti-foam additives. High rpm operation can result in aeration of the oil and reduced protection.
4. High levels anti-wear additives. These are compounds that provide protection against metal to metal contact during startup and under high load conditions where vibration can break down the oil film. The most commonly used anti-wear additive is a zinc and phosphorous containing compound that is now found only at reduced levels in automotive oils because it poisons catalytic converters in cars. Boats don't use cats.
5. High levels of anti-corrosion additives. Boat engines typically sit for long periods of time. As acids accumulate in the engine oil during operation, they must be neutralized by additives or metal corrosion will be accelerated. The longer a boat sits without running, the more the oil film will drain off the engine parts and corrosion becomes more of an issue. This can be minimized but not eliminated by proper oil additives.
So what does this all mean? Unless you operate you engine very gently and change the oil at least twice per season, automotive oils are not sufficient for good protection. Multi-viscosity engine oils such as 10W-30 are really 10 weight oils with a small amount of a viscosity improver added to keep the oil from thinning below a 30 weight at 212 degrees. The problem is that marine engine parts can get hotter than that at high load and rpm. Plus the viscosity improvers tend to shear at high pressure and temperature. That's why marine engine manufactures recommend straight weight oils or their own brands of multi-grade (like Merc 25-40) that do not contain any viscosity improvers. So other than using the engine branded oils, which by the way are all very good oils but cost a lot of money, what kind of oil should be used? Here is the dirty little secret. Look at the rating on the bottles of any marine oil. You will see that they contain a bunch of letters like SJ or SI. But the key is that they always also have a CH-4 rating. That means that they are certified for use in diesel engines. They use a standard diesel engine oil additive package that contains higher levels of anti-wear, anti-corrosion, and anti-foam agents than automotive oils. Combined with a shear resistant base oil, you now have a marine oil. Oh yeah, diesel oils already contain a shear resistant base oil designed to hold up under extreme pressure and load.
So there you have it. Use a diesel oil and you have everything you need to protect a marine engine for a whole lot less money than you'll pay for a branded boat oil. Back in Florida, everybody used 15W-40 diesel oils in big block gas engines and they held up for thousands of hours. There are straight 30 weight diesel oils available that would also be fine. Any synthetic diesel oil should also work great. I know guys who ran 15W-40 Amsoil AME in their inboards with great results.
Truth.
Cliff's notes: Just run HDEO "diesel oil". It's the same [censored].
apparently you did not read my questions. I am sure a 5w-40 did just fine as its not like these motors aquire huge numbers of hours. But ancedotal evidence still does not answer the reasons of why a specific type of oil is spec'd
I actually didn't respond to your post, but if you want a breakdown,, here goes:
Originally Posted By: DoubleWasp
Quote:
There is a lot of misinformation about the right oil to use for inboard gasoline boat engines. Some of it is propagated by the engine manufacturers in order to get you to use their own brand of oil. Remember that all of these engines are just marinized automotive engines. The 4.3 Mercruiser is the same engine used in GM cars and trucks. Marinization just uses a different cooling and exhaust system and spark arrested electrical components. All of the other other components are the same as the automotive engine.
But there are differences in how a boat engine is used vs a car or truck and that is where the different oil requirements come in. Boat engines are operated at much higher rpm and load conditions than a car or truck engine. So the properties of a good marine oil that gives maximum protection under those conditions are similar to a "racing oil" used for competition rather than on the road cars or trucks. However, racing oils are not designed to hold up well under conditions of infrequent use and high humidity. The important properties for a marine oil are:
1. Sufficient viscosity to provide protection during acceleration and operation at high rpm.
2. Resistance to mechanical shear. During operation under high speed and load, the oil molecules can align with each other under extreme pressure and the viscosity can dramatically decrease.
3. Anti-foam additives. High rpm operation can result in aeration of the oil and reduced protection.
4. High levels anti-wear additives. These are compounds that provide protection against metal to metal contact during startup and under high load conditions where vibration can break down the oil film. The most commonly used anti-wear additive is a zinc and phosphorous containing compound that is now found only at reduced levels in automotive oils because it poisons catalytic converters in cars. Boats don't use cats.
5. High levels of anti-corrosion additives. Boat engines typically sit for long periods of time. As acids accumulate in the engine oil during operation, they must be neutralized by additives or metal corrosion will be accelerated. The longer a boat sits without running, the more the oil film will drain off the engine parts and corrosion becomes more of an issue. This can be minimized but not eliminated by proper oil additives.
So what does this all mean? Unless you operate you engine very gently and change the oil at least twice per season, automotive oils are not sufficient for good protection. Multi-viscosity engine oils such as 10W-30 are really 10 weight oils with a small amount of a viscosity improver added to keep the oil from thinning below a 30 weight at 212 degrees. The problem is that marine engine parts can get hotter than that at high load and rpm. Plus the viscosity improvers tend to shear at high pressure and temperature. That's why marine engine manufactures recommend straight weight oils or their own brands of multi-grade (like Merc 25-40) that do not contain any viscosity improvers. So other than using the engine branded oils, which by the way are all very good oils but cost a lot of money, what kind of oil should be used? Here is the dirty little secret. Look at the rating on the bottles of any marine oil. You will see that they contain a bunch of letters like SJ or SI. But the key is that they always also have a CH-4 rating. That means that they are certified for use in diesel engines. They use a standard diesel engine oil additive package that contains higher levels of anti-wear, anti-corrosion, and anti-foam agents than automotive oils. Combined with a shear resistant base oil, you now have a marine oil. Oh yeah, diesel oils already contain a shear resistant base oil designed to hold up under extreme pressure and load.
So there you have it. Use a diesel oil and you have everything you need to protect a marine engine for a whole lot less money than you'll pay for a branded boat oil. Back in Florida, everybody used 15W-40 diesel oils in big block gas engines and they held up for thousands of hours. There are straight 30 weight diesel oils available that would also be fine. Any synthetic diesel oil should also work great. I know guys who ran 15W-40 Amsoil AME in their inboards with great results.
Truth.
Cliff's notes: Just run HDEO "diesel oil". It's the same [censored].
Originally Posted By: Anthony
I only did it for maybe 2 minutes at a time. The Range for this motor is 4400-4800 so maybe it was only 4800rpm but the tach read 5000.
Most of the time it will not be operated like that. I just wanted to see what it could do. I def kept my eye on the water gauge.
Here's the boat getting ready to go to it's new home.
http://i24.photobucket.com/albums/c18/abmobil/336_zpsdb67cd43.jpg
You are likely underproped.
I only did it for maybe 2 minutes at a time. The Range for this motor is 4400-4800 so maybe it was only 4800rpm but the tach read 5000.
Most of the time it will not be operated like that. I just wanted to see what it could do. I def kept my eye on the water gauge.
Here's the boat getting ready to go to it's new home.
http://i24.photobucket.com/albums/c18/abmobil/336_zpsdb67cd43.jpg
You are likely underproped.
Just curious, but how fast will that boat go? FWIW I use Delo in my 4.3 merc drive 18' Chaparral (1999) and it runs 4700 rpms at 52 mph top speed on GPS.
Last edited:
Originally Posted By: Silverado12
Just curious, but how fast will that boat go? FWIW I use Delo in my 4.3 merc drive 18' Chaparral (1999) and it runs 4700 rpms at 52 mph top speed on GPS.
I don't have it anymore, but It would top out at 45 on the speedo at WOT which was around 5000 RPM. I'm sure the speed was a little lower on a GPS.
Just curious, but how fast will that boat go? FWIW I use Delo in my 4.3 merc drive 18' Chaparral (1999) and it runs 4700 rpms at 52 mph top speed on GPS.
I don't have it anymore, but It would top out at 45 on the speedo at WOT which was around 5000 RPM. I'm sure the speed was a little lower on a GPS.
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