C7X46

As the title states see attached, universal averages are for 5W30 M1.

On a side note, I am using the same oil my LS based marine engine with similar results vs MFG recommended fluid.

Toddiesel

Are you saying it makes wear parts last twice as long (meaning the amount it wears is half as harsh as with 5w30) or that they wear out twice as fast (meaning the wear time is half as long)? I can't make heads or tails of that pdf.

tzoid9

C7X46....your statement confuses me. Your title says 15W50 Mobil One cuts wear in half and your sentence in the body of the post says universal averages of 5W30 Mobil One, which is what the 15W40 is being compared with.. The wear metals of the 15W50 are only slightly lower than the 5W30 and in some cases identical...the 5W30 wear rates could very well be within the specifications of the Corvette engineers. The additive packages are much higher in the 15W50, which is nice, but that doesn't prove the 15W50 engine is wearing at half the rate of a 5W30 engine. What am I missing here?

C7X46

Blackstone universal averages are the average wear numbers for LT4 engines using 5W30, compare the actual number to the averages.

C7X46

If my actual is half what the masses get running 5W30 what other conclusion would you draw?

Jims66

I think they may be claiming it because of the higher ZDDP numbers in the 15W-50, which is advertised as having a higher anti-wear package recommended for flat tappet cam engines. I've only used Mobil1 15W-50 since rebuilding my '66 L79 back in '90 when the ZDDP levels were just starting to be looked at by the Government.. ZDDP levels were reduced due to a Government regulation because supposedly high ZDDP levels hurt catalytic converters so it became a smog/pollution issue.

https://mobiloil.com/~/media/amer/us...pecs-guide.pdf

tzoid9

OK, let me try it another way...and amazingly enough, I am familiar with internal combustion engine oil samples...spent 40 years looking at them while trying to determine cause of failure in drive trains. Far from being an expert, but I have looked at them many times. The data that the attachment shows is contaminants and additives in a live engine oil sample (the column on the left) vs. the standard oil sample norms for that particular model engine with the spec 5W30 Mobil One in it.
If my interpretation is correct, then I believe the conclusion you drew may be incorrect. The wear metals PPM's are very close, sometimes the same between the two columns and I have no idea what GM/Chevrolet allows for wear materials in an XX hour running cycle. Technically, the hours on the oil is a convenient but very inaccurate way of measuring "oil life". The real way to do it is "gallons of fuel thru the engine". I don't know if Chevrolet has ever released that number for it's customers, but you can bet the ranch the engineers know that number. The additive packages in the left column (the 15W50 oil, I think) show healthier numbers and my guess would be that the 15W50 oil is used primarily for racing applications and the load factors on that engine in racing vs. street driving are off the charts, different/higher.

You could be correct with your statement that wear levels are much lower with 15W50, but I can't see that conclusion in the chart you provided.

Road machine

It is all I run in my 496 HO that powers my SeaRay 270 sundecker. The thing I notice the most is that coming out of the hole before I used the 15w-50 I would get a nasty piston slap....since changing over there is no slap at all.

tzoid9

I'm not sure of the parallel comparison of a Mercruiser 400+HP I/O in a pleasure craft vs. and a 6.2L Supercharged 650 HP Corvette engine. What I can assure you is, the boat industry is easy peasy on high horsepower engines and load factors....it is the very easiest application in the engine world, short of a stand by generator in a hospital. The load on the boat engine is created by the prop turning in water, whether the boat is moving or not. We used to test boat engine HP by putting the bow against a dock and after the gauges were installed, fire up the engine pushing the boat against the dock. Works great every time....glad you're using 15W50 in the Mercruiser, nice to know.

C7X46

I am using it in an Ilmor MV8 7.4, we are pulling almost 10,000 LBS with it heavily loaded for surfing and it operates all day just under peak torque. The factory fill was M1 5W-50 when I bought the boat, later in the product life cycle M1 15W50 was added to the approved list for the engine by Illmor. The 5W50 seemed to shear down around 30-35 hours and pressure dropped 10PSI hot, in back to back testing 15W50 cut wear metals in half. I would be curious to know what the lowest wear metals others have seen using the factory fill on a similar change interval.

tzoid9

I think you need to run the oil you want to in your car and in your boat....you're not going to change what I've experienced and lived with for over 40 years in the business and I'd bet, I won't change yours, either. No need for us to argue, I tend to believe the capabilities and knowledge of the engineers who designed the 6.2 in the Z06. I'll stick with them on engine oil. Hell, I'll never run the life out of my car anyway, it will very likely out last me, easily. Cheers............

andreas g.

Warp Factor

Wrong!!!!!
A car requires only about 15 horsepower to go down the freeway, and typically only sees about 10 seconds of sustained full throttle at a time
A boat may need 30-100% full power just to maintain cruise speed (depending on the boat, the engine, and what the owner considers to be "cruise speed"), and owners flat-foot their engines clear across the lake quite regularly.

Higgs Boson

I run only 15-50 in all my cars, including the ones with cats.

Warp Factor

OP, actually your "wear metals" with your 15-50 oil are about the same (or very close) to Brookstone's "universal averages" for LT-4 engines using 5-30, with the exception of lead. If my understanding is correct that LT-4 engines don't use lead-plated bearings, I wouldn't know how to explain that part.

However, you did put about twice the mileage on the oil, compared to the mileage Brookstone Labs claims they use for their "universal average", so you might be on to something.

MustOBeenYellow2015Z

For what its worth I too thought oil is oil & oil additives really don't help until I switched from Mobil 1 oil to this super trick super slick oil that I found out about that had a moly additive in it. Ran this oil in my race engine all season then took it to my engine builder to get freshened up. After tearing down the engine he called me & asked me if I even ran it.


*This was in my nascar oval track car with Flat tappet cam motor, going from Mobil 1 5-30 to 3-30 oil with a moly additive.

*The only oil that I know that has high levels of zinc in it is Joe Gibbs racing oil but it doesn't have the super slick moly additive in it.

C7X46

This is my marine application, and I absolutely love this engine, makes its rated power on 87 octane and shakes with cam lope.

20K for the upgrade and I wouldn't consider a boat of this type without it.

https://www.ilmor.com/Marine/Other-Inboard/MV8-74L

http://www.mastercraft.com/video/detail/46/trailer

tzoid9

I can't begin to guess where your boat horsepower knowledge comes from. Your statement about a car on a freeway is correct. Now take that car and make it a tractor trailer and pretend that tractor trailer is hauling an 80,000# load, on a hill....with a head wind. The load factors are huge, much greater than the loaded truck on a flat road and cruising at 70 mph. Your car on a freeway in Texas, cruising at 80mph, I agree, load factors are minimal. A boat prop cutting threw water can only provide so much resistance to an engine....the prop will slip in the water...you, of all people, experienced with motor powered boats, should know and understand this. I hope you really don't believe that in an overloaded boat cruising at max speed, whether at max throttle or not, is putting any kind of substantial load on the engine.

Widgeon5

You are incorrect about this. The fact that the prop "slips" somewhat in the water is irrelevant. The prop is sized and pitched to absorb the engines full horsepower and torque. The engine can't be worked any harder than this in a wheeled vehicle, or any other application.

solotronics

Interesting conversation. If you watch this video it's Mercury Marine talking about peak power vs durability in Marine and Auto applications. They mention the power numbers are "conservative" because as a marine engine builder the wide open throttle stresses on open water are much harder on an engine.

https://youtu.be/pNCIWLtdVKs