o2man98

What are you referring to???

Nominal = 50% @ "X" microns
Absolute = 98.7% @ "X" microns

The AMSOIL filter is absolute at 15 microns and the Mobil filter is absolute at 18 microns. The rest will go by the specific data mentioned.

All the figures above show the specific Efficiency at the specific Particulate Size.

Hydrocruiser

Amsoil 20W-50 Severe Service Racing Oil and their oil fliters are great...excelent choices.

minxguy

Yes, thank you. Ken

vandeano

Mercury Mercruiser 25W-40 Synthetic Blend Engine Oil...What are some comments on this oil???

Hydrocruiser

As with all blends you don't know the ratio of synthetic to conventional oil. In many cases it is usually only about 20% synthetic.

The Blend is for 4-stroke outboards that were shearing down the conventional oil I hear.

vandeano

I read somewhere that Mercruiser oil has additive ingredients for the marine environment not found in regular automotive oil. Any truth to that and if so what it the ingredient?

articfriends

You need to be 100% sure your rings are seated before converting your motor to synthetic oil or you'll be pulling it back out of your boat.Everyone gives the example of chevy corvettes coming from the factory with mobil one but I have seen motors that were NOT fully broken in converted to synthetic too early and if the rings glaze she'll have high leakdown rates FOREVER,Smitty

articfriends

If anything it might have extra zddp which is crucial in flat tappet motors,Smitty

vandeano

That might explain the problem I had with my rebuilt engine. Thinking it was a roller motor, I didn't know it would of been a problem. Im sure glad I used Mercruiser synthetic blend on my new crate.

Hydrocruiser

Here are some additives most premium oils have...Mercury has what I conisder to be a chemistry similiar to Kendall 40wt..in a sample we looked at of Mercury oil we found no special formulation as one might have expected...I feel the best oil out there because of it's tough base and extreme corrosion resistant formulation remains M-1 20W-50 V-Twin for the marine environment. No slam but Mercury is NOT in the oil business.

Characteristics of Additives
Additive Name Characteristics

Detergency & cleaning action Phenaltes, Sulphonates, Naphthenates Interacts with varnish or sludge to neutralize and solubilize.

Dispersancy PBI (Polyisobutylene) Succinimides Dispersants are soluble in the oil and have a polar end which attracts and binds to contaminants preventing settling and adhesion to metal surfaces.

Antifoaming Silicone Polymers (very low concentrations) Not really necessary for diesel engines in properly designed systems, but provides anti-foam in gearbox and also at the refinery during blending.

Pour Point Polymethylacrylate Used in SAE 30 grades and below to ensure point criteria are met.

Anti-wear load carrying ZDTP (Zincdialkyldithiophosphate)ZDDP (Zincdiethlydithiophosphate) Chemicals react with surfaces forming films which have a slower shear strength than parent metal.

VI Improvers Polymers of: Methacrylate Acrylate Olefin Styrene-Butadiene Increase in relative viscosity more at high than low temperature.

Rust and corrosion inhibition Sulphates, Thiourea type chemicals Chemically absorbed onto bare metal surfaces providing protection and neutralization.