When there was a magazine in print that Teague (Teague on Tech) replied to, he stated all synthetic oils, except AmzOil, made the rollers on the lifters slide on the cam and created flat spots on the rollers which ended up tearing up the cam. I call BS. Who is his sponsor...oh ya. Use synthetic it's awesome. When I used to run conventional oil it would come out black, which meant it was breaking down and not protecting the engine. Now I run synthetic in everything I own, change the oil at longer intervals and it comes out almost the same color.

If you want a true test buy a wix oil analysis kit 24077. You can buy them online or at any parts store that carries Wix, about $20. Try it with the old school oil then try it with synthetic. They give you results which will let you know what metals are found in the oil and where they could be coming from, based on what type metal is found, and if it is not an acceptable amount. They also tell you what the viscosity of the oil is when they test it. I did it with Mobil-1 after 15,000 miles in one of my vehicles. Everything came back great and viscosity was within 2 numbers of when it started.

Oil is suppose to get black. The "black" is the soot, dirt, combustion by products the the oils detergent/dispersant package is holding is suspension to carry these contaminates to the oil filter and get filtered out.

Black by no means the oil has broken down.

I change the oil in my diesel and within 1,000 the oil is jet black. Broken down, I hardly think so.

If you oil isn't getting black from use, it is not doing it's job. Find a different oil.

Ken

You are compairing diesel to gas??? Mobil 1 may not be the best oil out there, but I'm sure it does a good job. Maybe using a good filter, Wix, might also help me.

No expert here but have had good luck running Valoline VR1 Racing Dino oil SAE 40 or SAE 50. Also used Kendal Racing Dino Oil SAE 40 or SAE 50 in my Procharged 500EFI's with ZERO problems. I have nothing against synthetic just can easily get the racing Dino oils locally for less money and I like to change my oil every 20 hours just because. I also run a WIX racing oil filter.

Wish there was a easy way to research and learn about oil but its so confusing and impossible to find answers that are not biased.

That's interesting you run Kendall. There is an engine builder just outside of St. Louis and that is all he uses. I know a couple of guys that used him, he builds some nice reliable stuff.

ALL oil gets black with use, diesel or gas. Diesel just get blacker sooner.

Ken

Brad Penn (bought Kendall oil back in the early 90's) then Joe Gibbs make a dino oil also. Both are some of the best oils produced. Kendall is also a great oil. Swepco 306 oil is also a awesome choice. All of these oils listed have a high zinc content and properties that you need in marine applications.
Most of these oils are about 8 dollars a quart. Better pricing if you buy cases or gallons.

strange,but some oils are more expensive by the gallon...i know amsoil is...

Ive always ran the Valvoline VR-1 in my motors and had no problems, but my new boat has a 500efi in it and was thinking about switching to Royal Purple... kind of a toss up..

I would stick with the VR-1. good oil

Not sure where you get your pricing, but AMSOIL is not more expensive by the gallon. All their products are less per case and less per larger quantities.

Amsoil is popular so no discounts. Unless you become a dealer. Sounds like Amway to me. I used Amsoil and was not impressed for the money spent. If I had to pick a syn oil it would be redline or Joe Gibbs. Plus less expensive.
If you buy Brad Penn, two or mores cases you will get a discount. Swepco you can if you work or own a shop you buy at wholesale. Joe Gibbs I have not found any breaks yet. Shop around on line, you usually can catch a deal.

So, I've always run Merc 25W-40 dino until last year switched to Merc 25W-40 semi-syn in all 3 current 4 cycle marine engines. Always changed at 50 hrs std duty engines and 25 hrs high perf engines. I've got 330 hrs on 05 525's, 180 hrs on an 07 current 350 MAG, had 225 hrs on 04 496's, and had 500 hrs on an old 87 350MAG before rebuilt for tuliped valve. I've had no oil related probs I know of or is ignorance bliss? What is "wrong" with the Merc oils? :cartman:

Me too, my stock 502 mpi mags that have never been opened up have 705 hours on them. I was using the Merc. 25w-40 regular oil then switched to their semi-synthetic oil at about 400 hours. In that time I have been doing 50 hour oil changes, but I have been running the Amsoil synthetic media oil filters with Filter Mags (magnets) on them.

Brad Penn purchased the Kendall refinery in PA. Brad Penn has nothing to do with Kendall motor oil. Kendall motor oil is now owned by Phillips/Conoco. The other half of the old Witco Chemical, Amalie, is now located out of Tampa I think.

Ken

What about breaking in a new motor, run conventional then change to synthetic, or break it in with the oil your gonna run

Break your engine in with a high quality petroleum oil.

Once oil consumption stabilizes, run what ever you want.

Ken

100% agree!

Hello

It's an old theme
Now there is the Quicksilver 25w50, is this a good choice for the 500 EFI?

thanks in advance for your suggestions

Sure.
So is Mobil 15w-50
So is Valvoline VR 20w-50 conventional or synthetic
So is plenty of other oils. But above , including the Mercruiser oil, are the top 3 fav’s.

Hello

I just had 11 hours on my Mercury 500 EFI engine after complete rebuild.

The oil change ?

Quicksilver 25w40 synthetic blend or the last Quiksilver 25w50 synthetic blend ?

The best choice ???

thanks

most people on the boards are using Mobil 1 15-50, or something similar

This. Wally world has good price.

Hello

But in Europe,

not Mobil 15w50, not Valvoline .....

then run what ever you like, personally I dont like synthetics in a marine application

Great post, some great info!

Found this link, never seen this one before, shows all the Mobil one oils, and how they are actually different.

The 15W-50 is 1300 PPM of Zinc

https://www.mobil.com/lubricants/-/m...pecs-guide.pdf


What's interesting as well, they make a V-Twin oil 20W-50 which is 1750 PPM Zinc.

Oil debates are endless. Everyone uses different oils and 99% have no issues so they think their oil is "the" magic oil. The truth is nearly any oil will work in nearly any engine. Even the super duper engines..... 99 cent wal mart oil will work as well at $12 VTwin in 99% of marine motors. You will never know the difference after years of use.

that^^^^^^ well maybe not the 0W20 lol

Friction modifiers and viscosity improvers are the additives found in modern "car" oil that you DONT want in a performance marine oil.

Car oils use a lightweight BASE oil (the 15 weight in a 15w40) and then put in "longchain viscosity improvers" to yield the 40 number. A marine application will "chop up" and "use up" the viscosity modifiers pretty quickly, leaving the base oil only (the 15w).

The friction improvers/modifiers are added to make up for the removal of zinc and phosphorus (both of which are counterproductive in zero-emissions goals). These also are a poor crutch vs the proven (but less green) zinc and phosphorus.

So what Merc does is to mix 25w and 40w base oils..

And outside of Merc oil, you have to understand the "secret language" of modern motor oils

All 5wXX and 0wXX oils are loaded with boat-unfriendly chemistry.

All 20wXX oils are considered NON MAINSTREAM AUTO/TRUCK products and can get away with giving more of what you want and less of what you don't need. Keep that in mind.

Any oil labeled MOTORCYCLE OIL will be free of friction modifiers because otherwise the wet clutches would slip like heck.

Any oil labeled LAWNCARE or UTILITY oil will have more zinc and phosphorus in em. Mower engines are a similar duty cycle as a marine engine. Mower engines typically run flat tappet cams, which require zinc.

Racing oils are a mixed bag. Some are labeled racing oil in order to allow them to use a formulation that is desirable for motors and undesirable for catalytic converters - while still containing decent detergent package and good corrosion control. Other racing oils are true racing oils that are low detergent and zero extended anti corrosion additives and are designed to be run hard and immediately changed - that's not what you want In a boat.

Sooooooo. There's more to it than you'd think on the surface.

20w40 motorcycle/marine/lawnmower oil is your friend.

Nothing wrong with a synthetic as long as it meets the discussion above..

Full synthetic motorcycle oil is great.
V Twin labeled Mobil 1 is fantastic stuff.

But honestly, lawnmower oil is best value.

I always use only synthetic oil in my boat, mostly Mobile 1 or Pennzoil Platinum, no problems, I see no reason not to use.

Would an oil that had both high levels of zinc and phosphorus with friction modifiers be a good thing?

if synthetic oil was so slick that lifter rollers won't spin on the cam I want that oil.
GM says synthetic oil in my ZO6 and its got roller lifters and my guess all of the GM trucks, and sport utilities that have roller lifters and last multiple hundredhundreds of thousands of miles and roller lifters and cams are not the issues.

it was something Bob Teague said many gazillion years ago so It had been hashed out back then. Look at this thread starts hundred years ago awesome.
okay, back to present day. Oil threads just won’t die. Mobil 1 15w-50 and vslvoline vr1 conv for the syn and conventional wins.

I had premature failure once,..........:D
https://cimg1.ibsrv.net/gimg/www.off...fb64ecafaa.jpg

https://drivenracingoil.com/i-304978...arine-oil.html


Loaded with ZDDP for added protection, MR50 offers an application specific product designed for this demanding performance environment. Driven's certified lubrication engineers have worked with marine engine builders to develop a first-in-class synthetic product that delivers performance and value. Excellent protection for high performance marine engines. Ideal for flat tappet cams, big blocks and blown marine engines. MR50 contains rust inhibitors for winter storage and defense against ethanol blended fuel. Viscosity typical of 15W-50.

Been using Driven oil this summer

What's your opinion on Mobil-1 15w-50 which is popular choice here. Label states it has added zinc.
https://www.mobil.com/en/lubricants/...obil-1-15w-50/

thanks

What Pismo10 said on sept 13th. Most any all will work fine.
Multi viscosity oils used to be an issue in marine engines decades ago, losing viscosity, but with standard service intervals, no longer an issue.

But they are taking more and more zinc out of most standard automotive type oils, so one with extra zinc would be good for flat tappet motors, the zinc may cause less wear on them after hundreds of hours.

Just FYI, another oil brand.

i have used this for 3 decades. Schaeffer brand. Their 15w40 diesel oil. Use in everything except new vehicles due to viscosity.

Schaeffer stated in the 1800's making grease for wagon wheels. Half the price of other high tech oils. It's a conventional oil, not synthetic. But it matches most all specs of a true synthetic so it must be pretty refined. Actually just went to the Racing oil version of the Supreme 7000. Exact same oil with more zinc since they are being forced to reduce the zinc these days in non-racing oils.

I've got a 11hp snapper mower 30 years old and the mower is falling apart but no oil usage and no smoke. Not bad.
But like Pismo10 said....