25W40 what other oils can be used?

alwhite00

Active Member
May 31, 2010
1,809
Michigan
Boat Info
1997 250 Sundancer
Engines
5.7 EFI/ BIII
Looking for options for 25w40. Just seeing what other people use. 5.7 efi mercruiser.

LK
 
I use Rotella-T 15w40 in every thing I own. :thumbsup:
 
Here's my first and last opinion on the subject...if diesel engine oil is good enough for commercial trucks and heavy equipment fleets...it's more than good enough for a Chevy gasoline engine.

I second Wayne's testimonial. I use Chevron Delo 400 HD 15w40 in the boat, trucks, motorcycles and lawn mowers now. I'm also on a zinc additive regiment every other oil change (as recommended by several machine shop owners)
 
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Here's my first and last opinion on the subject...if diesel engine oil is good enough for commercial trucks and heavy equipment fleets...it's more than good enough for a Chevy gasoline engine.

I second Wayne's testimonial. I use Chevron Delo 400 HD 15w40 in the boat, trucks, motorcycles and lawn mowers now. I'm also on a zinc additive regiment every other oil change (as recommended by several machine shop owners)

If I had flat tappet lifters I'd be doing that. Thought somebody might be using Mobil 1 or something. I hate paying $10.00/qt. for Mercruiser 25W40 if there are others out there that will work. Does any other brand make that weight of oil? I called around a few auto parts stores and they act like you are crazy acting for that weight.LK
 
I use amsoil formula 4 marine 10w-40 in my 496s and everything else I own. They have been making synthetics for over 20 years. ihave been using it for the last fifteen years and I have never had anything break do to oil failure.
 
15-50 mobil 1 full synthetic, works great, can be had on sale for $5.99 qt. Napa
 
I also add 2 oz./5 gal of semi-synthetic 2 stroke oil to my gas. This is an old gearhead trick and is supposed to increase power and keep the top end lubricated. I also add this to my other motors (car, SUV, sports cars). Can't hurt.
 
I hate paying $10.00/qt. for Mercruiser 25W40 if there are others out there that will work. Does any other brand make that weight of oil?


$10 a quart? Where are you shopping? You can get a gallon for about $24 at my local West Marine and they show a list price of $27.99. Probably even less at WalMart. There have been tons of threads on oil here. Bottom line is people here use all kinds of stuff. Some use straight up Auto Zone oil to save 5 or 10 dollars on an oil change. The marine oils are recommended for a reason. There are plenty of threads here that explain those reasons.

http://www.westmarine.com/webapp/wc...toreNum=50366&subdeptNum=50396&classNum=50398
 
True Jason, But that mercruiser oil isn't full synthetic or even a synthetic blend. The minute it is blend or full synthetic the price jumps to near 10.00 a qt.
 
True Jason, But that mercruiser oil isn't full synthetic or even a synthetic blend. The minute it is blend or full synthetic the price jumps to near 10.00 a qt.

Correct but he originally said he was looking for 25W40 with no mention of Synthetic or Syn Blend. If he is specifically looking for Synthetic I would expect him to indicate that. Of course, even with Synthetic the same guidelines apply with regard to marine oils. You can get Merc Full Synthetic for about $7/qt if you purchase by the gallon from Merten Marine.
 
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$10 a quart? Where are you shopping? You can get a gallon for about $24 at my local West Marine and they show a list price of $27.99. Probably even less at WalMart. There have been tons of threads on oil here. Bottom line is people here use all kinds of stuff. Some use straight up Auto Zone oil to save 5 or 10 dollars on an oil change. The marine oils are recommended for a reason. There are plenty of threads here that explain those reasons.

http://www.westmarine.com/webapp/wc...toreNum=50366&subdeptNum=50396&classNum=50398

Wall mart - $9.99/qt - Maybe that was synthetic, I'll have to look again. The nearest West Marine is an hour away, Just looking for something I can get local. None of the auto parts carry it.

LK
 
Wall mart - $9.99/qt - Maybe that was synthetic, I'll have to look again. The nearest West Marine is an hour away, Just looking for something I can get local. None of the auto parts carry it.

LK

I doubt it would have been synthetic. I think there is now a Quicksilver labeled Merc Full syn but it probably would have been more than 9.99 but who knows. You may want to try Merten Marine. Regular Merc 25W-40 is 21.35/gal. Of course you will have to pay to get it shipped but at least won't have to pay tax. For something that is probably a once a year event for the average boater and the fact that you only have one engine to change, not too bad.

http://www.mertenmarine.com/servlet/the-Mercury-Oil/Categories
 
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When I had my Bonanza I would buy the oil in bulk cases from the local petroleum distributor. MUCH cheaper than buying it anywhere else. I am planning on visiting them for my boat oil also.


Sent from my iPad using Tapatalk HD
 
Looking for options for 25w40. Just seeing what other people use. 5.7 efi mercruiser.

LK
Al, straight sae 40 is acceeptable and can still be bought at some part stores, it says so in EVERY mercruiser manuals I've ever had and still does in my 05 496HO
 
Al, straight sae 40 is acceeptable and can still be bought at some part stores, it says so in EVERY mercruiser manuals I've ever had and still does in my 05 496HO


I can find straight 40W - I used it in my 86 260 on my last boat. Thanks for the info.

LK
 
I had a 97 250 just like yours, I ran nothing but sae 40 straight, the boat now has 1200 hrs. on it with new owner that has it now, never a valve cover off of it. My father was Chevron oil co. for 40 yrs, ran nothing but st.40, never a problem, I'm sure the nay sayers will chime in on this............Because there are alot of IKE's on here, " I know everythings"............lol Frequency is way more important than brands as long as you run acceptable weights.
 
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Its getting harder to get, but you can still get it. Never an engine problem, but I change mine twice a yr. And you can cross ref the filter to an ac delco, or wix from Napa and save maybe a buck or two. Napa also carries mercruiser eng coupler grease.
 

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