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350 MAG MPI oil
Black_Diamond
Member Posts: 5,439 ✭✭✭✭✭
I'll probably start a firestorm of thoughts on this, but in prepping to change my oil for haul out time, I was going to just use Mobil-1 15W-50, I ran the Merc full synthetic this season, but that is gone as you know and only the blend is available. So reading my engine manual, the recommended oil is either the Quicksilver 25-40W or a straight weight 40W (above 50F). It expressly in bold states not to use synthetics or oils with solid additives (I assume ZDDP), which seems odd. Mind you this is a manual from 2002 too. I'm not worried about the 15W-50 grade as the pour point on the synthetics is vastly better than a conventional oil of the same weight.
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Who wants to step into this discussion?
Past owner of a 2003 342FV
PC BYC, Holland, MI
PC BYC, Holland, MI
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JoeStang
Member Posts: 1,116 ✭✭✭✭
I've used the M1 15w-50 and my oil pressure is better, its still golden after a month or so and generally holds up better vs. the dc'd Merc fully synthetic stuff.
They probably dont recommend it because of the higher zinc and phosphorus levels for use with catalytic converters. Mine doesnt burn a drop of oil, and I figure the better wear protection is more important than POSSIBLY shortening the converters lifetime.
2013 276 Cuddy ~ 350 MAG / B3
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2004 Rinker 312, 5.0 Merc's, Bravo III, Lake Wheeler, AL
I may not be an expert that knows all of the oil ratings and additives, but I have used Mobile 1 synthetic oil in my GM vehicles (4 at a time including wife and kids) for the past 10+ years. I personally have averaged 50,000 miles a year on my business's pickups and have ran most of my vehicles over 150,000 miles, and one to over 235,000 miles ( and none needed oil added between oil changes). I remember people telling me not to use synthetic oils way back then. The biggest thing I did was to do routine oil and filter changes at 5,000 miles, not that I thought oil lubrication was exhausted, but I was concerned the filter life may have been exhausted.
I guess what prompted me to start using the synthetic oil was proof of the lack of oil breakdown from heat compared to conventional oil. I switched to running AMS oil 15W-40 diesel/marine (thanks Drew) this summer in my 2004 350 Mag MPI that I don't use ethanol in, but continue to run Mobile 1 in my cars and trucks. I have never had an engine (oil) related issue or major engine repair on any of my vehicles. I did have an issue with a premature camshaft failure at 50,000 miles but it was covered by GM because of a known serial number run of camshafts in my 2010 Silverado. It is funny that now GM recommends the use of full synthetic oil in their engines, with a Dexos rating. If I had used oil other than their Dexos rating it would not have been covered under warranty and they did do an oil change/use history. I know the Dexos rating has more to do with ethanol affects, but the synthetic oil is because of oil breakdown from heat and tighter engine tolerances. (Getting back on track) My opinion is that my 10 year old 350 Mag MPI with maybe less tight tolerances than todays engines is better off running on synthetic oil even if I pay a little more for oil.
On oil weight my early preference was a 10W-40 oil and ran that religiously thinking the heavier weight oil was better. But when discussing this with some engine professionals, I learned that when engines started having tighter tolerances (than when I did engine work) that lighter weight oil actually improved fuel economy and didn't cause as much drag on moving parts or reduced oil lubrication. My current 2014 Silverado 4wd with 5.3L gets in the 22-23 mpg range on the highway in warm temps, which is better than my wife's Equinox 4 cyl. AWD. Most of that is like MT has been saying recently about a bigger engine doesn't reduce economy but will improve it. Same with a boat as a boat engine works a lot harder than a car or truck anytime, accept that Equinox 4 cyl. works it tail off.
My 2 cents on synthetic oil. Just saying.
Rob
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All I've wanted was to just have fun.
it's a bit of a conundrum, no? The zinc protects the engines, as it adheres to hard parts that sit for months at a time- but it will kill those catalytic converters quick like if even a relatively small amount gets past.
on another note: I'm hating the prospect of changing out the Amsoil... the stuff still feels and looks like new... I can't wait to zip open the filter and see what all it trapped. I'm not sure how Amsoil does it, or why others haven't jumped onto it, but the stuff suspends ash but doesn't bind to it like other (even high end) oils... what I've learned, though, is you better remember to swap filters because the ash the oil isn't clinging to is left behind in the filter medium...
I think I'm going to run a Royal Purple filter next season...
Mark
2019 MTX20 Extreme
PC BYC, Holland, MI
What do I do with my 3 unopened quarts of Fully Synthetic bottles I bought to have in case of an emergency?!?!
Boat Name: King Kong
"Boat + Water = Fun"
the party line is: syn oil's detergents and additives don't break down with age as dino oil's detergents do... an engine accustomed to dino oil has deposits in nooks and crannies that the synthetic oil will disperse, suspending it and sending it all over the engine, ultimately to and often overwhelming filters.... As expensive a prospect as it is, if you're moving from dino to syn, the better plan is to schedule two changes no more than five hours apart- complete with filter.
if you're moving from synthetic to dead dinosaurs, you can treat is as any oil change.
Insofar as moving from merc dino to merc blend- and in what will seem as an about face: even dinosaur oil of today is better than it was even ten years ago... the label remains, but the contents of that jug haven't stayed the same. I wouldn't worry so much about the type of oil (dino, syn, or blend) so much as simply using a quality oil and attending to your scheduled maintenance religiously. you'll likely be just as good as anyone else using any other kind of oil (so long as it is a Marine/diesel rated oil).
diesel oil, for instance, has much of the stuff sought out by using marine oil... today's diesels use diesel particulate filters which undergo an extreme temperature session while the exhaust regenerates the DPF. The oil has to be capable of handing that circumstance, and it does- hence the re-formulation of Shell/Rotella's T series oil... those rigs use catalytic converters, too, and have to have something added to keep diesel fuel from bonding, as some of these designs (International, I'm looking at you) wash cylinders on the exhaust stroke to fuel the fire in the DPF.. this burns the soot off, but washing cylinders with injection on the exhaust stroke allows fuel to slip past the rings and enter the crankcase. the additives are also good for suspending water and other fluids, and in hopes to keep from discovering a milkshake in your crankcase. The reformulated diesel oils are also made to protect the catalytic converters, so they should be safe to use in marine catalyzed engines, too.
for most of y'all, I'd seek out a straight grade oil... the W in oil ratings doesn't stand for weight, it stands for Winter.. 10w40= oil that pours like 40 weight, but under heat retains the consistency of 10w., for instance. It can be purchased in huge containers from commercial trucking suppliers, from a gallon to a freakin' barrel. I know we got some hard core boaters here, but I'm thinking those of you who need to concern yourselves with winter grade oil are few and far between.
If'n I were y'all, my concern would be simpler than we make it, though I think we only make it so for conversational purposes... I'd choose a quality oil and stick with it, and pay attention to intervals as determined by an analysis. You simply can't go wrong if you follow that simple prescription, barring unforeseen catastrophic failure- which is usually attributed to bad maintenance (I'm guilty too, at times- hello gimbel bearing!) or something that went wrong with the fuel systems (making an excessively lean situation that no oil can protect you from). Choosing a quality oil (and filter!!), and sticking with it will yield consistent expectations and results..
All I've wanted was to just have fun.
PC BYC, Holland, MI
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I was like, "huh?"
According to the store owner, Mercury is still selling Full Synthetic Oil. It's just been rebranded. She can get as much as you want, no problem. And all that talk about it ruining the catalysts - well read the label, specifically designed for emission control catalyst engines.
Boat Name: King Kong
"Boat + Water = Fun"
Boat Name: King Kong
"Boat + Water = Fun"
PC BYC, Holland, MI
Go Steelers!!!
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PC BYC, Holland, MI
I don't know what to say but she has a lot of full synthetic on her shelf and said she recently ordered it. The bottle itself says it's formulated specially for EC catalytic engines.
For what it's worth, I'm going to the synthetic blend, so I know it's always available... For now. Lol.
Boat Name: King Kong
"Boat + Water = Fun"
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