What type of oil

mrtopknight

mrtopknight

New Member
Oct 3, 2006
361
Lake Mary, FL.
Boat Info
2001 182 Sport
Engines
4.3L MerCruiser w/ alpha one
What engine oil weight does my 2001 4.3L call for? Also, does it call for a special brand like the drive lube?


Thanks,
 
Marine engines run under significant load all the time which is far different from automotive applications. The viscosity enhancers and additive package in marine oil is a lot different than automotive oils, not to mention corrosion inhibitors. The additive pack is also one of the reasons marine oils are more expensive.
 
mrtopknight said:
What is so special about marine grade oil?
Click to expand...

A good quality marine oil is about twice the cost of a good quality auto oil. figuring you only need to change your oil once a year is it really worth trying to save $10 when you are talking about protecting a $10,000 engine?

Frank is right about the demands we place on a boat engine. You will run 4000 rpm for long periods which never happens with a car engine.

I just figure it is a small price to pay for a little piece of mind.
 
Merc 25W-40 is the recommended oil.

Marine engines generally run at high RPM's in more diverse environments than the automtive types.... marine engines are exposed to high levels of humidity... can be subjected to salt.... run hard at higher RPM and constant high loads... exposed to a bunch of stuff (banging waves, wakes, etc)... then we let them sit until the next use... which could be the next day... the next week.... or the next month... or worse. Merc's claim is that the 25w-40 is built for this type of Marine use.


I have always used Merc's 25w-40 and now use the synthetic blend 25w-40 (I have twin 4.3 MPI's). I change oil every 50 hours (yes I know the manual says every 100) and every other change I send a bit of the old oil for oil analysis. The wear is tiny.... even on my last boat where we put significant hours on the boat. The oil analysis guy often remarks how the oil has held up very well to the use....

The only advantage I can see to not using the Merc product... is saving a couple of bucks. I use the stuff because it has worked very well for me.... it means no questions about oil type at should a warranty item arise with either of the engines... and it seems to provide excellent results in the way of wear on the internal motor parts....

I think this is one of those discussion points that no one can agree on :smt001
 
fwebster said:
Marine engines run under significant load all the time which is far different from automotive applications. The viscosity enhancers and additive package in marine oil is a lot different than automotive oils, not to mention corrosion inhibitors. The additive pack is also one of the reasons marine oils are more expensive.
Click to expand...

Frank,

My owner's manual says to use the Merc 25-40 engine oil for 4-stroke engines, and NOT TO USE synthetic. I just talked to John at T.I.M., and he said that Merc is now recommending synthetic for all engines. (8.1 S Horizons).

Thoughts?
 
I used the regular 25w40 on my 5.0 Liter MPI.... and we put a ton of hours on that boat..... oil analysis reported very little wear at all.... I think the regular 25w40 is a very good oil as well. SeaRay Jim has some interesting info on how the regular 25w40 is used in the custom motor world.... maybe he will refresh our memories.
 
Jeremy,

Do you think they're recommending it for 2004 built 8.1 S Horizon's in a 2005 340? The book says no, but like TheAcademy5 puts it, now their name's on it.

I bought a new 1977 Honda Accord when I was in High School. In order to make it last, I put synthetic in it. It turns out, it was not recommended. The synthetic oil broke the head gasket down and caused the engine to wear out completely in 30,000 miles.

They helped rebuild it, but it wasn't any fun.

Also, how much do you pay for a quart? a gallon?

I paid 13.45 for a gallon of merc 4-stroke 25-40 oil, and they want about 17.50/gallon locally. How much is the semi-synthetic blend?
 
SYNTHETIC BLEND MERCRUISER (25W-40) ENGINE OIL
Specifically formulated and developed to meet the needs of:

High-output sterndrive and inboard engines.
Developed for the rigors of the marine environment.
Industry-leading corrosion protection.
Features premium-grade synthetic and mineral-based stocks with specially designed marine grade additives not required in automotive oils.
Outstanding lubricity for internal engine components to reduce wear, scuffing and scoring.
Eliminates thermal breakdown under extreme RPM, temperature and heavy-load conditions.
Rigorously tested to guarantee warranty protection for MerCruiser Sterndrive and Inboard engines.

There's the answer - It's good to go!
 
Oils are comprised of a base oil(s) and an additive package. Synthetic base oils are superior to petroleum (dino) oil in virtually every measurement: 1) higher thermal (temperature) ability, 2) better cold starting flow (lower wear), 3) higher temperature/high shear ability e.g., the oil does not break down under severe loads, 4)l lower volatility (less burn-off) therefore, less oil consumption 5) less burn-off or oxidation means less deposits, e.g. varnish and sludge deposits.

"Real" synthetic oils, group IV (PAO) and/or group V (esters) base oils, cost 3 to 4 times that of a petroleum base oil. Expensive synthetic base oils also use more expensive additive packages. than groups I to III petroleum oils.


The Bottom line is that synthetic oils are vastly superior to dino oils. Any chemist or chemical engineer will tell you that. You simply can't hydrocrack and filter petroleum enough to eliminate the contaminants in the oil or produce a "slippery" uniform molecular structure..
Finally there are several excellent synthetic oils available, including: Redline, Amsoil, Motul and two or three others. (Mobil 1 is no longer a "real" synthetic, its a group III dino).
I would recommend any 100% synthetic 15w-40 or 20w-50 over any petroleum (mineral/dino) oil made on the planet.
By the way,although I don't know who is blending the Merc/Quicksilver synthetic BLEND oil, but I would bet that it is has no group IV or V synthetic base oils, but rather, is a group III hydroisomerized petroleum oil which can be "marketed" as a synthetic given a court ruling in 1999 (Mobil v. Castrol). While more expensive than most petroleum oils, I would certainly recommend 100% SYNTHETIC oil. That's what I use. Good luck with you lube decision, it is the life-blood of your engine.
 
slack.... I am embarrassed to say we only have 67 hours on the 280 in 9 months since delivery. We would traditionally be around twice that right now in a typical year. We have had a ton of family and work commitments that have just killed our fall and winter boating :smt009

The place I use for oil analysis is Blackstone Labs...

http://www.blackstone-labs.com/ they send you the kit for free and they seem to process your sample the same day they get it... and you will receive a PDF via email immediately after they finish. A paper copy comes in the mail a few days later.... very cool stuff.
 
I went to change the oil out on the 8.1 S Horizons today, and while I was upside down in the bilge, I noticed that there aren't any drain plugs! I thought I could pump most of it out, then open a drain plug, and drain every last drop, but there simply aren't any.

There is a small fitting opposite the dip stick tube. It looks like it's there to plug the hole that the dip stick tube could go in if you had to put it on the other side, but no drain plug.

Just like the book says, they hold 9 QUARTS each !!!!!!!!!!!!!! That's a lot of pumping.

The dealer swore it would only take 7, but I bought 5 gallons of synthetic, and they took most of it.
 
Jeremy
Thanks for the link to Blackstone Lab
Odered my kits today
FAQ say engines should be run for 20 min
Guess I will have to wait till splash (68 days and counting)
Or do you think I can send in sitting sample ?
Heated storage.
Dan
 
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