been using Torco MTF with 8 oz of Pro Blend for years along with some buds in Fl and after 100 hour inspection was told gear sets look like new .....

How much power are you running? Do you run them hard?

a bunch , and we run em like we stole em and Randy @ Marine Drive does our service .

Anybody using Amsoil or any other brands?

Heard from Fountain service they have run Amsoil and Torco at same intervals in sixes and Amsoil looks new at drain compared to dirtier appearing Torco.
Still running Torco in mine, have a case of Amsoil left from Bravo days. May try it out in dry sixes.

I think our MLW18 would be the ticket for your dry sump 6's.

We've been using amsoil mcf for 2 seasons based on bob teagues recommendation, and everything looks brand new at every drain
We change oil about every 10- 15 hrs to be on the safe side.

MCF, is the absolute best ticket! Oh, by the way, its a motorcycle oil.... Lighter viscosity, cooler op temps, and great protection!!!

What is the cost per gallon for your MLW18 and what are specs on it?



I dont doubt Bob for a second, but I've heard in the past that he uses this 10-40 MCF in his race boat and if this is what he basises his suggestion on, I'm a little skeptical about using it in my own pleasure boat for a couple of reasons... First, I'm sure his stuff gets torn down and inspected far more frequently than my pleasure boat ever will. If something is wearing or needs addressing, it will get caught and replaced. Second, I suspect part of why he runs this is to reduce drag (speed increase), but it comes at some cost (protection). Third, I believe Bob's only running 525's in front of those 6's... I suspect Marvel Mystery Oil would work just fine for the light loads those drives see!

Again, the protection part is what makes me a little nervous about using the 10-40 in the drives. I believe it only has a API GL-1 rating and AMSOIL even says not suggested for use where a GL-4 or GL-5 fluid is required. I would think the AMSOIL Synthetic Marine Gear Lube might be a better fit and offer better protection, but there would be increased drag (over the MCF) from the increased viscosity...

I'm not saying the Amsoil MCF is bad to use, I'm just voicing my concerns for discussion.

10 - 15 hours behind 700 hp ? ran 1000s thru Teague platinum + and did'nt change fluid at 10 hour intervals