Hydrocruiser

I verified with Merc today that their 25W-40 does not contain polymers that expand with temperature. "It is a blend of straight weight oils that behave similiar to a 25W-40". Blackstone Labs calls it a "37wt oil". I call it marketing.

"They do not specifically recommend conventional multi-vis polymer containing oils" (as the polymers can shear down quickly and you can be left with a 20W oil)... but rather only a straight weight oil such as a 30wt in cool regions and a 40wt in warmer regions and a 50wt for flat out racing. They further stated they are now testing synthetic oils.

Now my case for Mobil-1 20W-50 V-Twin

It is a unique straight 50wt oil. (I got that straight from Mobil's chemists). It pumps like a 20W-50 because synthetics with high base stocks have lower pump rates.

It is in my humble opinion because of this and the extensive anti-corrosion and long termed storage film strength retention. The best oil for any marine engine... as it flows like a 20wt..protects as a 50wt at all times....has zero polymers...and the highest (1800ppm) ZDDP levels of any oil I know of with a flashpoint of 518*F and outstanding detergency...and no friction modifiers to potentially raise concerns of "flat-topping"..... it is what I call "The Beast in the Black Bottle".

You can mix V-twin with MX4T because both are straight weight oils....both are unique in that fact as they pour and pump like a multi-vis.

FYI: 15W-50 M-1 does have polymers in it to get to a 50wt under heat... BUT... being a synthetic it will not shear down like a conventional multi-vis can.

Why pay top buck for a conventional oil when you can have something to brag about in your oil pan?

minxguy

OK, so Merc addressed the blending of the 25w-40 by using a heavy base stock and a pour depressant, no polymers. Perhaps that's the truth, who knows. What bothers me is, if the sample of Merc oil tested by Blackstone labs was new, unused oil and the lab came up with a 210 F viscosity of 37, which tells me that it is a heavy 30 wt, this particular sample did not even meet the viscosity on the label. The label says that the product inside is a 25w-40 and it is not. People are buying this thinking it's a 40 at 210 and they are getting short changed. What you should post is the actual SUS or cST viscosity of the fluid and see how it compares to the industry accepted specs set by the SAE, not some number like 37. I don't call it marketing, I call it sad, misrepresentation, and against the law.

The wrong polymer in the wrong application can shear down and have the oil end up it's original base oil. I will buy that.

Mobil's legal dept would never allow the marketing dept to put a straight 50 in a bottle and call it a 20w-50. If the bottle says 20w-50 the product is multi-viscosity. You are claiming 2 different classifications of viscosity. Extremely hard to do with a straight 50 base stock, synthetic or not.

You can mix MX4T and V-TWIN because they both have similar chemistries, not because they are both straight weights (which they are not, see above). If you wanted, you can mix straight weight and multi-vis oils. Having similar chemistry is the best way to approach this, so try to use the same brand but............as a rule of thumb the public doesn't.

The only type of lubricant that doesn't shear is a straight weight....because it does not contain polymers. All polymers shear, quality ones just don't shear as much. Ken

Hydrocruiser

I hear ya ...but fact can seem stranger than fiction somtimes. Your points are noted Ken.

As you know MX4T and V-Twin and non-API rated products...while 15W-50 EP is a multi-vis API rated oil...it does have polymers in it...but didn't shear at all after 40 hard offshore hours in a 502 mag last summer.

The question remains...is Merc's 25W-40 API rated? I think not...but not sure...I think that API vs Non-API ratings is the legal loophole.

Pismo10

It's getting heated..........

Hydrocruiser

....gotta love a good debate

minxguy

Hydro, I am holding a bottle of MX4T and V-TWIN. The MX4T says API SG,SH/SF and JASO MA. The V-TWIN says API SG, SH/CF and also JASO MA. The V-TWIN has diesel ratings on it because HD recommends a diesel rated oil if you cannot get OEM. As far as the rating on Mercs product, I don't think they would have to put one on because "it's the product that they recommend". Like Harley did years ago with their "360 rating". Like Polaris does with their AGL, no API rating or SAE viscosity, It's what they recommend.........................What bothers me more than anything is that Merc has 25w-40 on the label and according to Blackstone the oil is a heavy 30. The product is out of grade before you turn the key. I guess you get what you pay for. I probably wouldn't buy a outdrive built by Exxon/Mobil. Ken

Hydrocruiser

..it does not have the API Service Symbol or Starburst on it...that's the loop hole?

What does the API Starburst Certification Mark tell you?
"The API Starburst certification mark allows you to easily identify those motor oils that have passed a comprehensive series of performance tests and product quality audits".


It may be one thing to print API specs on a bottle and another to get it certified ??

Hydrocruiser

FYI..Wallyland has 15W-50 EP M-1 in Gallon containers again in our area.

Rebel_Heart

I know this is swaying the discussion to a lower level, but how do I counter an engine builder who insists that I should use Valvoline Racing 40w and just change every 20-25 hours because the synthetics are harder on seals and I am just wasting money? If I do change, how long after break-in oil to change to Mobil?

Hydrocruiser

Most feel breaking in on a conventional 40wt or Merc's 25W-40 is the way to go. 20-40 hours max. before going to syn oil.


Seals:



The first synthetic oils (and still some brands on the shelf today) did not have specific organic phosphates and aromatic hydrocarbons added into the products and as a result leaks were common. These additives cause a chemical reaction with the elastomer in seals to cause slight swelling and improve and/or maintain patency of the lubricant in the engine and hence avoid any potential for leakage or seal damage. (fyi....many conventional oils have always had these additives present over the last 25+ years.)

You know you are safe with Mobil-1; Amsoil; Penzoil and the rest of the BIG brand names. I hear that some syns like Redline Racing (non-detergent and non-seal additive containing) is one to watch out for as well as some less popular syn oils. .

One other comment...nobody on OSO specifically while using a synthetic oil has voiced concerns about leaks...we just don't see it happening in real life.

Synthetic oils are highly purified base stock products that can take a lot of heat and shear and not break down. They tend to have the best additives at the right doses. The motorcycle syn oils (ie. M-1 v-twin) do not have friction modifiers present and any worries of the oil being "too slick" and any subsequent problems potentially resulting are totally alievated.

It's all about myths or facts at this point.