www.iFourWinns.com

I wanted to change my oil before haul out. I have some questions. How many litres/gallons per 5.7 engine do I need to get? Can I use 10W30 car synthetic? Does using a brand like Royal Purple, Amsoil, or Mobil1 make a difference? Thanks ahead of time.

Shaun

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Vista 318 2007

Approx 4.5 quarts.

10W30...NO....Much to thin for a hard working marine engine. Straight 30 minimum (or even 40weight for Hot Climates).

Also, deafwish has recently pointed out that the marine oils have more anti-oxidents

Organic oil should be changed every year. Synthetic can go up to two years, but many people on this forum change every year anyway.

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"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

More discussion going on about oil (marine vs automotive) here:
viewtopic.php?f=11&t=12269&p=115315#p115315

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"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

For the record, a 10w30 will have the same operating viscosity (100C) as a mono grade 30.
Both of which are questionably too thin for most Chev based marine blocks.
I would be far more confident in running something along the lines of a 15w50 or a 20w60 with a late API spec'.

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2011 Four Winns H180 SS.
Aussie built Mustang 2800.
SOLD - 1997 Four Winns Horizon RS

The standard Mercury Marine oil is 25-W40

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Jeff

'14 Cruisers 380 Express "Simon Sez"
Merc 8.2 Mag MPI 380
DTS B3X, (x2) Axius Premier


(SOLD)
'08 V318
Merc 350 Mag MPI 300
DTS Seacore, B3 (x2)

I run 15w40 and find my oil pressures to be too high, even with a fully warmed engine.

The oil pressure gauges peg at 80psi on plane. 20-40psi at no wake speeds.

I keep finding the dipsticks out of their tubes 3-4"

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1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21

I would at least use a 10-40w oil. Remember, boat engines work a lot harder. No coasting down hills for us.

I run 20w50 in mine, and have yet to see any negatives from it.. Have not seen the Oil Pressure run too high either... Only negative (not really) is you about have to shake it out of the quart like a Ketchup bottle... j/k

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2004 Four Winns 328 Vista
1997 Larson Cabrio 290 - sold
1988 Rinker Fiesta Vee 248 - sold

That would not have anything to do with oil pressure...there is zero oil pressure in the oil pan. There is only pressure in the internal pathways of pressurized oil in the engine. Your dipstick issue is most likely vibration.

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"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

I have used straight 30,40 (Chevron Delo 400) and the Merc 35/40. All worked well with good oil pressures but I feel the additive pack in the Merc oil is best if you have a boat under warrantee. Dipsticks coming out of the tube suggests vibration or a loose locating bracket.

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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

Ahhh Ok Ill check the dipsticks and maybe find a way to get them to stay in their tubes.

Btw, was at O'Reilly and Walmart on my lunch hour today, there is a MIR $5 rebate for jugs of Shell Rotella T5/T6 synthetic or synthetic blend Heavy Duty motor oil (just were $21/each at WM, less $5 MIR = $16 for synthetic heavy duty motor oil!). It comes in 10w-30 and 15w-40, also I think a 5w-40. Even if you dont use this on your boat, if you have another vehicle that uses one of those grades, its a pretty good deal. Just a heads up.

Personally, Im going to switch from 15w-40 to 10w-30 when I change the oil the end of this season. I think with the Michigan climate 10w-30 Rotella Heavy Duty oil will be just fine. Right now I use Mobil Delvac 15w-40 because it was on sale for $8 per jug after MIR last year.

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1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21

.................... or internal crankcase pressure due to piston ring blow by, maybe the PCV not venting air through properly.; the dipsticks fit pretty snugly in the tubes so if there is any pressure in there that can't get out any other way, I could imagine they could be pushed out ( not due to any oil pressure theough)..

The dipsticks are both not very tight in their tubes. Maybe I can bend the tube flange a little and re-test. Both engines have 170 hours and they dont burn any oil so I cant see blow-by being a cause.

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1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21

Yeah, It probably isn't an issue with those engine hours. I do know that if I don't push the dipstick firmy home on my car, it'll move out an inch or so in normal driving ( the dipstick handle has an O ring which pretty much seals it in the dipstick tube).

I have used Mercury 25W40 oil in our last three boats that we have owned with 5.7 litre engines.

I plan to purchase a couple gallon jugs of 25W40 in Michigan next week while attending the Metro Fall Boat Show over there. This Mercury oil is cheaper in the US as compared to here in Canada.

Mike.

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Current Boat
- 2001 Four Winns 328 Vista "Hour Decision"
- 2010 310 Mercury Inflatable

Previous Boats
- 30' Doral Prestancia
- 25' Doral Citation