www.iFourWinns.com

I know people like to try different things with oil but we all have to keep in mind that a boat motor is under more stress RPM wise than a car engine, you have an engine and a single speed transmission, that's it. So at cruising speed most I/Os are turning 3200-3600 rpm, most V-8 car engines are only turning 1800 rpm in overdrive on the highway. I don't think that standard multi-vis oils will hold up in marine use, and in fact what Merc (25-40) and Volvo (syn 30) are recommending are not typical multi-vis oils.
I have a 20 year old 4.3 OMC Cobra that has done nicely on straight weight heavy duty Chevron Delo 400. Syn multi vis oils do have an advantage of not using viscosity index improvers such as conventional oils do but still I'd follow what the manufacturer says, after all under normal conditions you are changing once a season.

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88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

I'd like to personally thank everyone who has replied in this thread without mentioning Bob.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

Yeah........he IS the oil guy isn't he?


When you talk to people that actually work in the "Marine" repair industry, NO ONE talks much about oil (brand) related failures.

EVERY oil has been tried successfully. The NMMA specified FC-W for boats that sit in salt water marinas for months on end. If you trailer your boat and keep it in a garage you can probably use just about anything if you change it once a year or so.

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1987 Four Winns Liberator 211, formerly OMC 460 King Kobra powered, replaced in 2006 by a 1997 Mercruiser 454/Bravo III

Straight 30W Valvoline.

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One of 4 Previous (Sold) Boats:
2000 Four Winns 268 Vista

Current Boat: 2004 Chaparral 235 ssi cuddy

Me too. ^^^^ Manual calls for straight 30W.

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Troy
2008 Centurion Avalanche
1994 Four Winns Horizon 180 SE 5.0L OMC Cobra (Sold)
2002 Ford F150 Harley Davidson Edition (http://www.nhtoc.com) 378 hp & 465 tq at rear wheels
2008 Honda Accord EX-L w/Nav

QuickSilver Mercury Marine 25W-40 for my 298 Vista.

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Current Boat: 2000 Four Winns 298 Vista
Previous Boat: 2000 Carver 406MY

I use Volvo 30 weight synthetic sold at you local dealer. It's pricey, but one oil change a year will not break the bank. I am a firm believer in using what the manufactuer recomends.

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1998 Baja Boss 252 7.4L MPI Bravo 1 (SOLD)
2007 FW H200SS 5.0GXI (Sold)
2004 Chevy Silverado 2500 Crew 6.0L (tow vehicle)
1991 FW 170 Freedom 4.3L (SOLD)

I disagree, It's more like the car "pounding" up a 6% grade with a 5000 lb trailer on the back in 3rd gear at 3/4 throttle continuously. It doesn't take anywhere near as much HP to make a car go down the road at freeway speeds as it does to make a boat run across the lake at medium to high planing speeds. Marine engines work MUCH harder than do similar engines in a car at freeway speeds.

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1987 Four Winns Liberator 211, formerly OMC 460 King Kobra powered, replaced in 2006 by a 1997 Mercruiser 454/Bravo III

Unlike my race cars I would rely on my boat maintenance for my dealer, Winnisquam.
Ryan says stick with Volvo 30 weight synthetic which the manufacture recommends and I am with him…
It is not worth to play with it.

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08 H260 VP 8.1Gi DP.....Previous
2013 Crownline E6 Merc 8.2MAG BIIIX, DTS/SC

My dad and I have ran Pennzoil Synthetic for years, SAE30 only, just as your manual says. Hence what I am running in mine.

My dad works for FRAM and they recommend this for marine engines, due to the constant RPMs of the engine, a multi viscosity weight oil isnt recommended for the water.

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Rob

Present: 1999 Formula 280SS
Past: 1989 180 Horizon

http://www.robcamerondesign.com

Im going to use Valvoline 30w VR1 p/n 223 its got ZDDP and is great for older flat tappet engines like mine.
Take Care Gregg

Unless I missed it ......

Nobody has mentuioned how the marine spec oils have a higher degree of anti-corrosion protection, due to the more humid environment of a marine engine .... and the typically longer "at rest" periods, between runnings.

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Gordon Arnold
New Hampshire

2003 268 Vista ..................................................................Prior: 97 245 Sundowner

Gregg,

That's a good idea. When I pulled my 460 out of the Lib, SEVERAL lobes were flat on the cam. (it's a wonder it even ran at all!!)

I might also attribute the cam failure to the Slick-50 my brother ran it in too! I don't know what oil he ran ........he had a dealer change it for him every year or so..... (I would NEVER run ANY additive in any oil in any engine!!) I can only assume that the dealer put straight SAE30 like the manual suggested.....(but they did leave the drive without oil once.....and a second dealer filled the drive wrong.....(drive failed in both cases!!)

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1987 Four Winns Liberator 211, formerly OMC 460 King Kobra powered, replaced in 2006 by a 1997 Mercruiser 454/Bravo III

You're absolutely right.

That's why there's a fairly new rating for 4 stroke marine engine oils recommended by most or all the marine engine manufacturers.

NMMA FC-W

http://www.nmma.org/certification/progr ... s/fc-w.asp

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1987 Four Winns Liberator 211, formerly OMC 460 King Kobra powered, replaced in 2006 by a 1997 Mercruiser 454/Bravo III

Very good information. I changed mine with Pennzoil synthetic 30w, but now I'm going to go with the Volvo or Quick Silver next time.

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Mike
Smithville, MO
08' Hayabusa, 2011 Subaru Outback, 03' Infiniti G-35 S.C.