Dusty Times

I have always ran Mobil-1 Synthetic Oil in all motors. I have 500 efi's now and I'm not sure if I should run 5-30 or 15-30?

Active Mike

Between the two I would run the 15W/30. Have you ever tried race 50 by Royal Purple? Great oil.

Dusty Times

I have never tried the Royal Purple but have considered that or Amsoil. For some reason I bought a couple more cases of Mobil-1 5w-30. Don't no if I should run it or not?

splashandburn

Most of the prior posts that I've seen on this subject recommend the 15W-50, not the 15W-30

Hydrocruiser

I read through a lot of the previous oil thread; Bob's oil center site and called and talked to a few major high HP engine builders along with personal experience with a few brands of synthetics and dinos. The consensus is that there is no consensus about everything but here is what I found to be generally accepted and not my personal feelings necessarily:

-Synthetics outperform dino oils no matter what the API ratings. Those are minimum standards synthetics well exceed. Synthetics in the gear case reduce particulate matter and the drives run cooler. Mercury HP gear lube has antimony to help cushion the gears in it so it's mostly a synthetic formulation with good reviews from my marina mechanics as well. I have always used Merc HP but am switching to Amsoil gear lube next change as I hear it is possibly a notch better with less metal fragments on the drain screw magnet by a friend who uses it now. He notices a difference using 80w90 MT-1/GL4 rated lower end gear case marine oil by Amsoil.

-Mobil does not recommend extended intervals past manufacturer recommendations.

-One high-end builder dosen't feel comfortable with RP because they found it does weird things when and if mixed with gas. They go with Mobil 1.

-One highend builder uses only RP along with one dealer of high end boats; the dealer does not like how Mobil 1 is hard to clean in the bilge and that being the only complaint. Amsoil claims to be superior to Mobil 1 and RP which is "Moly" based and can settle out. Third party tests and never a law suite with the superiority claims made by Amsoil. Whereas Castrol was sued by Mobil for making claims against them.

-Amsoil is the only company that has supposedly never been taken to court for making claims against all other synthetic oils for superiority as they show independent data from 3rd party sources as having a product with a recommendation for extended use BUT with a couple oil filter changes using their ultra premium filter that captures particles less than 10 microns in size and not a regular commercial filter. So now you get into high-end filters and changing them a couple times if using the oil for extended periods. They recommend regular oil change intervals in severe duty use.

-Amsoil 1:100 synthetic oil for 2 strokes ought be used more concentrated in commercial applications to as much as 1:50. But hardly no smoke and no fouling. 1:64 works best for me. In a friends outboard and my lawn equipment. A definite winner here.

Troutly turned me on to Amsoil and I like it better than RP and better I would say to Mobil-1. I like either the Amsoil 15w40 Marine or 20w50 Marine oils with added corrosion protection. I will use a filter that captures particles down to 10 microns like the Amsoil filter or the Mobil-1 filter. I will not however extend drain intervals past the manufacturers recommendations. That's just me.

So in short the industry is going to synthetics and only Amsoil is the only manufacturer promoting extended intervals past the manufacturers recommendations with certain parameters to observe with filters and type of service, especially if a turbo is involved.

My take is:

-Frequency of change is key in the marine environment no matter what anyone tells me I will use the best Oil and Filter but not extend drainage periods.

-There is a significant advantage using a "high-end oil filter"

-Synthetics outperform conventionals

-Thanks Troutly for turning me onto Amsoil I like it a lot so far as it showed me not all synthetics are the same. I like Mobil-1 a lot but Amsoil best. I order it i a large container from their website http://www.amsoil.com/distribution_centers.htm
very reasonable shipping using ups or fed ex ground and immediate order attention and shipping. They also just came out with a new oil for heavy working 4 strokes that is 0w40. It is actually a single weight oil but would perform in those ratings compared to a conventional oil. Great for Lawn tractors/equipment and 4 cycle snowmobiles and personal watercraft. A special formulation to reduce foaming and extra additives to keep the internals clean and the oil free flowing. So my hats off to Troutly and a few others who have used this product with great results for telling what they use in the oil thread.

Finally I know a lot of you use conventionals and regular filters with great results. Not trying to sway opinion just sharing info.

zachsam

Hi all: my first post here after joining.

RP, Redline, Amsoil are all great oils.

Interesting comments about RP (settling out, doing weird stuff when mixed with gas, extended oil change intervals). Tres turned me onto it when I was with him in 95. I owned the race and industrial RP distributorship here in St. Louis for 5 years, and worked with racers from all communities (NHRA - Pro Stock cars and bikes, roundy-round, Indy, offshore, tunnel boat, jap and harley cycles). We put together some interesting new "concoctions" directly w/ the factory that were tested by these guys. Never had any complaints/concerns about settling out, nor mixing with gas. We also advertised running extended oil change intervals, and had done extensive testing with numerous large over-the-road trucking companies (2000+ trucks). The Illinois HP was also using it on an extended drain interval (not sure if they still are). But we didn't have our own filters like Amsoil. Mobil 1, Castrol, Valvoline, etc. etc. are what we often refered to as "me-too oils"....they spend more of their money on advertising than putting it back into the quality of the product (just an opinion).

For better oils like RP, Redline, Amsoil, "viscosity, viscosity, viscosity" is not nearly as important as film strength, so lighter oils can be run (I'm not recommending ignoring the factory warranty), with the added advantage of increasing HP and reducing operating temps (a lighter oil creates less heat and dissipates it better). We ran RP41 (15w40) in inXS blower motors, and RP21 (5w30) in the aspirated race motors. The pro-stock boys and Nascar (during qualifying) were running RP9 (0w10), along with some lighter oils we made that were never "assigned" a name, and the Indy guys ran RP11 (5w20) on the Ford Cosworth turbo motors....I kinda miss those days of receiving "blind" faxes with HP number comparisons....sometimes we'd have to wait for a phone call to see who was doing what.

Also remember that the better oils will resist emulsification.

Regardless of what oil you choose, get a good oil AND air filter.

Thx...hope I don't sound like a salesman.

Steve

Hydrocruiser

Thanks for the info on RP. Thought this might be of interest for Synthetic users ;info from 3rd party tests on RP vs. Amsoil. It's obvious that not all synthetics are equal. I have heard that Amsoil, RP and Redline were "premium synthetics". After reading this info I had concerns about RP; what do you think?

http://www.performancemotoroil.com/Royal_Purple_info


http://www.performancemotoroil.com/Dyno_test

zachsam

Wow...I'd have to go back into the dregs of my memory to post a technical response to the article, but I don't have the brain cells left (I'm 40....over the hill, you know). RP always had a bulls-eye on it's back....maybe that was a compliment.

Dynomometer testing can be extremely subjective....there are a lot of variables that come into play. I'm not doubting that it outperformed RP in that instance....you need to review data over the long haul (just for the heck of it, I did a search on dyno comparisons between RP and Amsoil, and that article is showing up everywhere....they're marketing it to the hilt).

I do question though why the heck anybody would run a 20w50 in anything.

Thx....good luck with your choices, and safe boating.

Hydrocruiser

It's the first article and the "Moly" concerns that caught my eye.
Here's another site basically quoting the same things and showing excessive wear in a test using Redline.

http://www.usasynthetic.com/page33.html

Dusty Times

I never guessed I would have got so much info on this post.

I actually feel like I learned alot about synthetic oils today.

Thanks