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Which engine oil to use

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charles4

New member
OK

I'm new here and I have been searching for the truth to which oil to use in our 2012 4.3 MC .
I search and Mercrusier web site keeps coming back as error 404.
Mercrusier says recommended oil,but if I do not used will it void the warranty?
Does it need to be synthetic?
What I've read and what I've been told are extreme.

I appreciate all knowledge and Thank You
 
Mercury has ceased production or branding of their Full Synthetic 25w-40. They are now recommending their Synthetic Blend 25w-40 in all 4 cycle applications.

Bennett
 
Using almost any oil product/manufacturer will NOT void any warranty.

I was not aware merc sold a synthetic oil for motors............they have for the longest time sold 20w-40w regular oil for all motors.

Myself and many other like to use Mobile 1

I use Mobile 1 20w-50w in my 350/5.7 (1987)

So I would say any oil of a minimum wieght of 15w-40w but no higher than 20w-50w.

WHat ever brand you like is fine.

My reccomendations would be

Mobile 1
Valvoline synthetic
Napa synthetic (valvoline in a differnt bottle)
Of course Mercury motor oil wether synthetic or regular.
 
how many hrs do you get from Mobil 1? ...I use straight 40wt. pennzoil.change every season.@25-40 hrs. Reman mercuiser 4.3 v6 vortec 1997
 
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I change it once a season....typically use it for 50 hrs or so.
Tuff to use it as much as i did years back as I have a motorcycle so depends on how hot it is.
I use Mobil 1 20w-50w Vtwin oil in the bike.

Used Mobil 1 10w-30w in my 1996 gmc 4x4 for 18 years until i sold it this past spring.
 
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NO

$25.00 per 5 quart jug............$5 per quart........plus tax of course........here anyway

BJ'S here has 10w-30w on sale from time to time, a 6 quart box for $26.00 I buy 2-3 boxes fo rthe truck.....

I but 2-3 jugs at wally world

the 20w-50w VTWIN is tough to get cheap........typically $12.00 a qrt but i only need 3 per change.........
 
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Hundreds of thousands of marine engines have run over the last 50+ years on straight mineral 10W-30 or equivalent grades without any failures related to the oil. Most marine engine failures of parts that are in the oil path are, I suspect, related to misuse of the engine (my engine sounds funny after I ran it for a hour at full wide open throttle). With annual engine oil replacement on RECREATIONAL engines that only see 10s of hours of annual use , full synthetic, IMHO, is overkill. Even synthetic blends are of marginal value... again, just my opinion. While synthetic and synthetic blends are supposed to reduce wear, most marine engine issues I've heard of are not wear related, most are corrosion/water ingestion related.
 
Well oil type usage is a large question.

What I will say and what I do know is,

Most synthetics are not 100% synthetic. They are blends....True 100% Synthetics are expensive. So for the sake of argument when I speak to synthetics I am speaking to BLENDS such as Mobile 1. It is not a 100% pure synthetic.

Most synthetic oils cost about the same as regular oils these days. especially when on sale!!

Most nonsynthetic oils when abused leave a lot of sludge in a motor, Synthetics dont.

Synthetics withstand much higher temps before viscosity break down. (would work great for some boaters as they over heat ther motors a lot.)

I am not sure 10 hours of recreational use is the right number........that would be only a day or two.........

Most manufacturers of high quality/performance auto's use synthetic oils......some specify and use very exotic ones that cost a lot like BMW and Mercedes etc.

The key is to keep it clean and keep it fresh.

I have not used convention oil in so long.....I started using synthetic oils in the 1980's........
 
Keep it simple, If you have a warranty on your engine still from Mercruiser, use their recommended oil. If your engine fails for any reason, including the oil, it will be their problem.
 
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