Merc 5.7 i/o oil viscosity

[Don S]

Re: Merc 5.7 i/o oil viscosity

This is why oil threads are a waste of time.
GM doesn't make the engines Marine, that is what Merc and Volvo and several other marinizers do.
What works for automotive, doesn't necessarily work for marine.
If you don't want to do what the manufacturer(marinizer) recommends, then use what every you want.
Someone somewhere has used it with no problems and thinks it's the best thing since sliced bread.
Since most boaters use there boats only 30 hours a year, but spend 500 hours tinkering with it, who cares what they use. They could probably go 20 years without changing the oil and think it helped.
What people use means nothing without oil sample specs, so why post "It worked for me" ????????

 

[Aloysius]

Re: Merc 5.7 i/o oil viscosity

Not that this matters to the OP, but I would think its because GM is not the ones who are paying for warranty claims.

If my engine was under warranty and Mercruiser says to run panther pi$$ in the engine. Guess what. Ill be at the zoo in the big cat section with a plastic cup...

I don't know about panther pee, but I've seen plenty of "snake oil" used.

for "warranty", no argument. As a matter of practice AFTER the warranty, any GOOD approved oil by GM works for me.

Oil related engine failures are essentially a thing of the past. Todays lubricants are so superior to a decade ago, stuff doesn't fail. We just took apart a Honda VTEC, driven like it was stolen for years, and it was PERFECT inside.

 

[pwpns]

Re: Merc 5.7 i/o oil viscosity

One of the classes that I took for my Mechanical Engineering degree was a materials class with a lab in which we performed tests on different weights of oils ( straight and multi-viscosity) to see which ones broke down first. The straight weight oils performed better everytime(would reach higher temps before breaking down). You only use non-detergent motor oil in air compressors and engines that dont have oil filters. Detergent oil suspends the dirt and transfers it to the filter which helps keep sludge from building up in the motor. Detergent oils also have additives that help the oil from breaking down.

 

[PitchFork]

Re: Merc 5.7 i/o oil viscosity

Why fight it use what the Service Manuals recommends and call it a day.

Yes Merc 25W40 cost more than 10W-40 but that is want Merc specs so that is what I run. Changed every 80 hours along with the outdrive gear oil and yes I use what the SM calls for Merc High Performance. Unlike most boaters I know I put 150 hours on my boat this season.

Just my 2 pennies worth,
PF

 

[fossill]

Re: Merc 5.7 i/o oil viscosity

GM doesn't make the engines Marine, that is what Merc and Volvo and several other marinizers do.

Actually GM does make the engines Marine. They engineer and build them. A whole division at GM is dedicated to just that. The only thing that Merc and Volvo do is buy from GM and bolt their outdrive to them. Nothing get marinized after the fact other than a few stickers installed, thermostat housing and exhaust risers added.

http://www.gm.com/vehicles/innovati...engines/specialized/marine/marine_engines.jsp

 

[Howard Sterndrive]

Re: Merc 5.7 i/o oil viscosity

Actually GM does make the engines Marine. They engineer and build them.

and, they don't recommend 0W, 5WXX, 10WXX, or 15WXX oils in them in marine applications unless fitted with an engine oil cooler (i.e. Volvo Penta apps)


I think Mercruiser has some input in the design, btw.
If it wasn't for Mercruiser, GM would not be building marine anything.
If you order 100,000 of an engine, you probably get more input than stickers on the valve covers.

 

[Aloysius]

Re: Merc 5.7 i/o oil viscosity

No one has mentioned the new generation engines. If you have VVT, you CAN'T use a "thick" oil..screws up the cam advance/retard system.

Since most of you guys seem to be cool water boaters, the argument is meaningless. Any 10-30 or thicker will be fine. Personally, I run 15w-40, no oil cooler, 80 degree water temperature, 175 degree coolant. Rebuilt engines last year..Engines were spotless inside, bearings were like new after 30 years.

 

[Dakota47]

Re: Merc 5.7 i/o oil viscosity

Its hard to beat a good HDEO like Shell Rottella 15W40, Chevron delo 400 15W40, Mobil Delvac 15W40.. you can get Shell Rotella T semi synthetic 10W30 or 15W40 at Wal-mart for $11.50 for 5 quart jug. Personaly i run penzoil 30WT in my 4.3 V-6 .

 

[Howard Sterndrive]

Re: Merc 5.7 i/o oil viscosity

Since most of you guys seem to be cool water boaters, the argument is meaningless.

there's no argument, just guys like you not reading...the guy is in Texas
I've been to Texas... sounds like many here have no idea what the climate there is like. It is hot, the water isn't "cool" relative to other bodies of water on the planet

Any 10-30 or thicker will be fine.

no it won't, which is why Mercruiser does not recommend it anywhere, let alone Texas.

 

[Howard Sterndrive]

Re: Merc 5.7 i/o oil viscosity

Its hard to beat a good HDEO like Shell Rottella 15W40, Chevron delo 400 15W40, Mobil Delvac 15W40.. you can get Shell Rotella T semi synthetic 10W30 or 15W40 at Wal-mart for $11.50 for 5 quart jug. Personaly i run penzoil 30WT in my 4.3 V-6 .

if you can't beat, why don't you use it?

 

[Alpheus]

Re: Merc 5.7 i/o oil viscosity

Its hard to beat a good HDEO like Shell Rottella 15W40, Chevron delo 400 15W40, Mobil Delvac 15W40.. you can get Shell Rotella T semi synthetic 10W30 or 15W40 at Wal-mart for $11.50 for 5 quart jug. Personaly i run penzoil 30WT in my 4.3 V-6 .

That makes no sense.

"I think the best beer in the world is Budweiser. Its cheap,plentiful, and the taste cant be beat. Thats why I drink Coors Light..."