No I have no idea if they will withstand up tp 10% contamination...

I just read that alot of guys are using Mobil1 with no issues and that a automotive oil NOT Marine..

All I can tell you is I just drained my bravos that were full with Merc Hi Perf oil and had some water drain in the bucket from the outdrive and that oil wont absorb any of that water..so not sure how that help if I get water in my outdrive??

You are going to need some type of agitation, like would be provided by the gears in the drive, to mix the water and oil.

I do not know why Merc says that or why it does not mix well with other gear lube.
You can mix synthetics and dino oils just fine in engines.

Has anyone used LE lubricants 1605? What were the results?

OK, asked the same oil chemist about that - he says the emulsifier will not keep the oil/water mix in suspension for long periods of time, but that it's purpose is to prevent water from being the lube for the gears - ie, to allow the water to disperse in the oil and not cause harm when running. Better emusifiers and larger doses will keep the emulsion longer, but not forever. The corrosion inhibitors are what prevents the rusting when water gets in the drive.

Horror story: I had an outboard that lost the shift seal once (in the top of the drive, but under water). Lost every bit of the oil, but I never knew it. I ran it at least two weekends (5-6 hours) like that. Tore it down, and everything was in great shape, a little light rusting on one bearing. Replaced the bearings/seals and ran it a few more years efore I sold it. Only had 125 hp running through it though...

so its there to keep them from mixing and becoming one..makes sense,,

Thanks

I use it or the more expensive 9920 in all the v-drives that I rebuild, best lube available in my opinion. Jim Wilkes uses it in all the v-drives and outdrives that he services. Rex Marine sells both but it is not in their catalog yet, have to call and order. Here is a link www.le-inc.com

Both are automotive gear lube...right?

My thoughts:

If you are running less than 300 ft-lbs of torque thru an Alpha drive, then run whatever MARINE spec drive lube you want to run. Your concerns are water emulsion, and gearface lubrication.

If you are running less than 450 ft-lbs of torque thru a Bravo, then run Merc Hi-Perf in it.

I keep hearing people ask why not to run auto gear lube, and the answer is - Because there is no benefit to it, and if you get water in the drive, you are asking for trouble.

If you are running your drive with WAY over rated torque load, then you want to use something better. Several have been mentioned here.

My own experience was on an outboard. A Merc 225 with an upgraded Alpha lower ran fine for several hundred hours. I replaced the block with a later model finger ported one, changed the port timing, changed the tuner, remachined the heads, went to velocity stacks and 14 petal reeds, the list goes on. Since I was seriously raising the power, I rebuilt the lower unit with new parts and filled it with Merc Hi Perf. After break in on the fresh motor, the day I started pulling WOT runs, the lower unit ate itself up. When I rebuilt it, I put the same parts back in, shimmed them the same way, and refilled with Amsoil Marine Synthetic. No problems. That lower unit is still together with about 50 hard hours on it.

The problem there was NOT that the Merc lube was poor, it just wasn't extreme enough to work in a unit that was being fed MUCH more power than intended. Additives can help, as well as starting with a lube with more shear strength and EP properties.

Just depends on what you're putting it in.

MC

I have run the NEO oil that has been mentioned this season, and I am draining it saturday and pulling one drive apart to check wear.

Hopefully I find nothing beyond normal wear. I will report my findings on sunday.

Smitty