M-1 EP = Extended Performance...as in extended drains...but they do have more ZDDP to achieve that and the components of ZDDP are EP lubes...confused yet?

Amsoil Marine Synthetic Lube has shown good results last season. I like the "seal conditioners" they use specific to outdrive seal materials that help prevent leaks and water damage. It is thinner and that means it can shead heat faster and better and also the lower viscosity means less paracitic loss.

It is the one to beat in my humble opinion.

Some of the engine oil additive manufactures ie;Duralube, used a chlorinated paraffin additve in their product to claim EP. Ken

Chlorinated paraffin’s:

They show how their oil will perform in a pressure test that has a torque wrench that puts pressure on a bearing and a round but rough surface that is turning in the test oil. They show how by adding their oil the wear is greatly reduced. This can be done with household bleach but you would not want to put any of that in your engine because it’s corrosive. The Chlorinated paraffin’s are also corrosive to the light metals in your engine. The lead in your engine bearings is subject to corrosion or acids that can build up. When the chlorinated paraffin’s come in contact with moisture or water of any kind they turn into hydrochloric acid and can become acidic to the lead in your bearings. So the reduction in wear shown by the torque wrench test is only one realm of wear that goes on inside your engine. Acidic or corrosion wear is another type and that is why I would never use an additive containing any type of chlorinated product.

Do not use any oil additive that claims EP protection in a engine for reasons stated above. They should only be used in a application that is sealed, ie;a differential, transmission, transfer case etc. But if you are using a quality product, you shouldn't have to additize the lubricant with an additive. The blender should have done that for you. All lubricating oils are a balanced chemical formula, by adding an aftermarket additve you no longer have a balanced formula and could be doing more harm than good, like adding an EP product to you engine oil. Sure it looks good when demonstrated with the Falex Bearing Tester, but in the real world it not the best application. Ken

Some you have lost it.. EP with the Mobil 1 is for extended performance not Extreme Pressure as they put in Industrial Gear Oils. The EP package put in those "Industrial" oils is for the shock load that is put on the gears. No one in their right mind would put in EP additive in a motor oil. And yes, there are some EP's put into closed systems as stated in there above.

Regards

Phosphorous and Zinc are both potentially used as extreme pressure additives and are present in lubes and as anti-wear additives in oil...it all depends on the molecular form and content %.

Best regards!

Kudos you sound like my ExxonMobil engineer. They aren't used though as a EP in auto world.

I was asked if too much ZDDP is bad...

Answer...usually not if the manufacturer added and tested it. If too much is added after manufacturing then it's possible to have too low a detergency ratio and the oil can sludge up.

A few asked me what I would suggest putting in their drive case this summer.

Well I decided that if a company deserves your business they should make a product specific to marine use.

So that's either Mercury Hp or Amsoil Marine Synthetic

...my money is on Amsoil Marine gear-lube this season as i have heard many stories of how it will not foam...handles water better than most and has "seal conditioners" other's may not...