Can't seem to find SAE 40 oil anywhere.

[ScotWithOne_t]

Straight 40 seems to be like bigfoot... everyone says it's what you're supposed to use, but nobody carries it.
Wal-Mart--of all places--has SAE 30, and most auto stores have 15W-40. I'm guessing the straight 30 would be the better choice if I can't find 40W anywhere, since the 15W-40 would essentially be 15W when hot, right?

 

[Fordiesel69]

Re: Can't seem to find SAE 40 oil anywhere.

SAE 30w is just fine. And so is 15w-40 if it is diesel rated.

Its the frequency of changing the oil and filter that is more important than what you are using. Oils today are very robust than lets say 1980 or 1990 oils.

 

[elkhunter338]

Re: Can't seem to find SAE 40 oil anywhere.

If you need to 40w to maintain oil pressure, buy 30w and add some powerpunch.
I like to run alittle powerpunch in my gear boxes, boat engine and such.
It will keep the oil thicker and lubricate very well.

Or use some 15/40 diesel grade and add some power punch.

 

[ScotWithOne_t]

Re: Can't seem to find SAE 40 oil anywhere.

What makes diesel oil different than any other oil? I get the feeling I'm overthinking this. I've been using 10W-30 in my 5.0L Mustang track-car that sees engine temps around 250 degrees.... oil pressure is pretty low at idle when it's that hot, but upper RPMs it's fine. My boat engine never get's very hot, so maybe I just shouldn't worry about it.

This is for a Merc 5.7L, BTW.

 

[Howard Sterndrive]

Re: Can't seem to find SAE 40 oil anywhere.

30WT will be fine, also 20W50 or 25W40

not sure why you are asking about diesel oil difference, but main difference is ability to disperse soot.
Diesel burns black and sooty if combustion is incomplete. Since it is a modern crime to allow that soot out the exhaust pipe, the piston rings are designed to allow it to pass into the oil. If gasoline engine oil was used, that soot would quickly clog the engine oil filter. Diesel oil holds the soot in suspension until the next oil change.

That's why modern diesels turn their oil black so fast.

 

[royal0014]

Re: Can't seem to find SAE 40 oil anywhere.

Look in out of the ordinary places. My wife picked up some 40wt at Fred's the other day (Dollar General-type store).

Even more fun trying to find non-detergent motor oil.


<<)))(((>>

 

[ScotWithOne_t]

Re: Can't seem to find SAE 40 oil anywhere.

30WT will be fine, also 20W50 or 25W40

not sure why you are asking about diesel oil difference

I asked because other posters recommended I use diesel grade 15W40.

I misunderstood the oil nomenclature. I thought that 15W40 meant it had a viscosity range of 15 to 40 (15 when hot, and 40 when cold). Further reading reveals that the "W" is for "winter" and a 15W40 will flow like a 15 weight when it's cold out, but still lubricate like a 40 weight. So, I've learned that a 15W40 (or even a 10W40, for that matter) is in effect a 40wt, but it just flows better if it's cold out because polymers have been added to it.

15W40 it is.

Now, to start the arduous task of figuring out what size oil filter a '96 Merc 5.7L uses.

 

[Fishermark]

Re: Can't seem to find SAE 40 oil anywhere.

... everyone says it's what you're supposed to use, but nobody carries it.

"Everyone says..."

I love oil threads!

If you want to know what Mercruiser recommends, here it is:

Application Recommended Oil
All MerCruiser engines Mercury MerCruiser Full-Synthetic Engine Oil, 20W-40, NMMC FC-W rated

IMPORTANT: Lubrication requirements for catalyzed engines differ from the requirements for non-catalyzed engines. Some marine-grade lubricants contain high levels of phosphorus, which can damage the catalyst system on MerCruiser engines. Although these high-phosphorus lubricants may allow acceptable engine performance, exposure over time will damage the catalyst. Catalysts damaged by lubricants containing high levels of phosphorus may not be covered by the MerCruiser Limited Warranty.

If Mercury MerCruiser Full-Synthetic, 20W-40 oils is unavailable, use the following lubricants, listed in order of recommendation. If you are servicing a catalyst engine, use these for short periods of time only.

Mercury/Quicksilver 25W-40 Synthetic Blend, NMMA FC-W-rated 4-cycle MerCruiser oil
Mercury/Quicksilver 25W-40, NMMA FC-W-rated 4-cycle MerCruiser oil
Other recognized brands of NMMA FC-W-rated 4-cycle oils
A good-grade, straight-weight detergent automotive oil according to the last row of the operating chart below.

 

[TilliamWe]

Re: Can't seem to find SAE 40 oil anywhere.

As Fred says, look at the chart.

HD40 oil is available at Autozone. (Pennzoil is what I used)

 

[Don S]

Re: Can't seem to find SAE 40 oil anywhere.

Now, to start the arduous task of figuring out what size oil filter a '96 Merc 5.7L uses.

Since you don't want to use the recommended filter, it's a Chevy 350, how arduous can it be. :facepalm:

 

[ScotWithOne_t]

Re: Can't seem to find SAE 40 oil anywhere.

Since you don't want to use the recommended filter, it's a Chevy 350, how arduous can it be. :facepalm:

It's not that arduous. I was being facetious. It's just another one of those things that will probably not have an easy, straight answer.
Forexample, not all Chevy 350s use the same oil filter. My boat is a '96, and in 1996 GM produced several vehicles that had a 350.
According to Fram's online catalog, a Camaro uses a PH30, a pickup uses a PH5, a Corvette uses a PH3980. I'm not sure which one will fit. Are they all the same thread and diameter, just different can heights?

Even more fun trying to find non-detergent motor oil.

Wait, what? Is a Mercruiser 5.7L supposed to use non-detergent oil?

 

[royal0014]

Re: Can't seem to find SAE 40 oil anywhere.

wait, what? Is a mercruiser 5.7l supposed to use non-detergent oil?

no


<<)))(((>>

 

[jopes]

Re: Can't seem to find SAE 40 oil anywhere.

Orielys had cheveron delo 40wt out here. It is what i have been using.

 

[Don S]

Re: Can't seem to find SAE 40 oil anywhere.

It's just another one of those things that will probably not have an easy, straight answer,

You are way over thinking this. Go to your favorite auto parts store that sells the brand of filter you like (Fram for example) and tell them you want a Fram oil filter for a 1996 Mercruiser 5.7L. They have marine cross references in their catalog.

 

[RogersJetboat454]

Re: Can't seem to find SAE 40 oil anywhere.

The different filters are a usually different capacity's. A truck filter for example is usually a little bigger. The Corvette filter may be a little smaller to fit in a tight space, or may be intended for the LT5 engine (interestingly enough, an entirely different 350 designed by Mercury Marine for Chevy). As Don said, a good auto parts place should have a cross reference between marine and auto filters.

As far as finding SAE 40, NAPA has never let me down. They have their own house brand SAE 40 which is really Valvoline in different clothes. I also know for a fact they have catalogs on hand to cross reference oil filters, and can give you a Sierra marine filter if you absolutely need a marine filter (which you don't) ...