"Best" OTC dino 20W-50 out there ???

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666
Location
Triad, NC
I need some opinions on the best dino 20W-50 out there that is also readily availble over the counter. I am especially looking for the strongest additive package since it will be used in a marine engine. I have not spent much time researching 20W-50 so any help would be appreciated !!!
 
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6,156
Location
Buffalo, NY
Well, I think Kendall no longer sells 20W-50 (I think it's a "semi-synthetic" 10W-50 since they've changed hands), but if you can find it on the shelf, by all means. I've been told that Castrol GTX 20W-50 is very good, as is Pennzoil 20W-50 (which is still rated SL I believe). But I won't argue against anyone advocating Havoline or especially Valvo. VR-1. But then again, this isn't my old 84' RX-7, favorite car of all time.
 
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4,284
Location
Central Wisconsin
Unless they've changed in the last few years, marine inboard/stern drive engines use a 160º thermostat. Engines run on the cool side. 50 weight oil seems a bit thick for those engines. My 2¢
 

Alex D

Thread starter
Messages
666
Location
Triad, NC
Quote:
Just out of curiosity, what marine application calls for 20w-50? Most that I've been exposed to lean toward 15w-40.
Mercruiser8.1S inboard engines in a 340 Sea Ray Sundancer
 
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297
Location
Denver CO
Engines in marine applications tend to turn a lot of sustained rpm, much more so than in a car. Also the oil tends to sit for long periods and condensation can build up in the motor over the days, weeks or even months that its not in use. This is why I prefer a dual rated synthetic 15w-40 in these applications. The synthetic base stock, stout add pack and high TBN should help keep the oil from breaking down and becoming contaminated. Favoites on these forums include: Amsoil AME, Delvac 1, and for the money Rotella T.
 
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606
Location
Monroe, OH
I've always liked Castrol 20W-50 for the old Benzes and BMWs we've had. Low consumption and quiet operation in what seem to be much looser engines then you would find in a Honda of similar vintage. Many owners of old-school German iron would agree. I got some Maxlife 20W-50 on clearance at Target a couple of years back for <.50/qt. I consider it okay for use in my lawnmowers. Seriously, as noted above, any oil meeting the oem weight and service spec should work just fine.
 

Alex D

Thread starter
Messages
666
Location
Triad, NC
Quote:
Just out of curiosity, what marine application calls for 20w-50? Most that I've been exposed to lean toward 15w-40.
All Mercruiser gas stern drive and inboard engines call for their Merc 25W-40 and if that cannot be had, ONLY 20W-50 is recommended as a replacement. Synthetic is specifically not recommended.
 
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4,819
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Southeast
3 of us that run together with merc 5.7s have all really liked rotella 15-40. 1 yr/50-100 hr oci doesn't seem enough for syn from our own experiences.. M
 
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13,132
Location
By Detroit
Well Valvoline VR1 is supposed to be nicely packed with zddp to the tune of about 1250 ppm zinc and 1150 ppm phos if my memory serves me well. You can go to valvoline.com and look up the zinc and phos in the product info sheetm, but I know it's around an SH level (1200-ish). Comes in 10w30, 20w50, and SAE 30, 40, 50, & 60.
 
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