Meet the new King of the Hill:
More data later in the text.
Very good related thread here on the forum.......check it out
http://www.network54.com/Forum/424840/message/1140004511
I’ve seen some recent postings about synthetic oil, and it’s about time I update my opinion on the subject. I’m still very high on synthetics, and wouldn’t consider using anything else in any motor I really cared about. I’ve used Mobil-1 15W50 in my marine 427s for several years now, and they seem to like it, so I can say “it works for me”. Based on cost, performance, and engine condition, it may not work for you, but one thing is certain, and that is “synthetic oil is simply a better performing product” than the alternative.
Some oil just comes with dirt allready in it. Ever see a can of the old Quaker State or even Castrol? It was always advisable not to pour all of it in the car, as it was already starting to make sludge in the bottom of the can. Why would you want to pour the sludge on the bottom of the can into your motor? Good base, I understand, and good oil, but it came with "dirt" already in it, and it burned with lots of ash buildup, and some of that stuff created sludge like it was going out of style. If you can see sludge in a fresh can of oil, just think what it's doing in the motor. I suspect some of these oils will "look" dirty a lot sooner, because they "are" dirty sooner.
Small amounts of oil gets by the oil control and combustion rings on a piston, and it burns with the fuel, as a natural function of engine design. Different types of oil burn with different results. The science is vastly improved over the time when most of our Commanders were built, and our old motors can benefit greatly by the improved science.
The one of many good things with synthetic products, is the fact that many of them burn with little or "no ash" build-up. This keeps the motor cleaner, as there isn't as much burned byproduct to clean, and this is one reason the dipstick may look cleaner for a longer period of time. It also avoids carbon build-up in the combustion chamber and detonation. Detergent qualities of a motor oil are intended to clean the soot, blowby, etc., and just because an oil may look dirty, it's still able to do the job. Oil burning byproducts are just part of the cleanup needed, as a rich burning motor will create a lot of internal soot. Diesels put an entirely different demand on oil too, and diesel-specific products must be used.
The prime benefits of a synthetic are; better heat resistance, better film strength, less breakdown, less friction and therefore cooler running, less combustion products to have to clean up, faster flow on startup where lots of engine wear occurs, and better lubricity (anti scar resistance) on the 4-ball wear test. As far as I've heard, they have no downside in the detergent cleaning side. Pure and simple, it's a better product.
Amsoil, in particular, is marketing a marine version, and a diesel specific marine version, and I understand one of the main difference in this product is the anti corrosion additives that are specially important to the marine environment. You won't find any major truck lines running big rigs without synthetic oil, partially for the longer change interval, and partly due to the better performance (less friction, better mileage, longer lived engines).
This isn't to suggest mineral oil isn't good, because there are some very good choices. The engineered synthetic oil products are just better every time they're tested head to head.
Since synthetics come in many different types, including a turbocharger specific formulation to resist cook-down due to the higher temperatures, it's important to NOT use some of those ultra light formulations in a big loose engine like a marine 427 or 454, for instance. Since this is my opinion, I would suggest anyone interested not take my advice, but check with the tech department of the particular oil manufacturer you're interested in, for your specific needs. In the interim, I want to share some of the information I have researched to form the opinion I have.
I checked in the past by interviewing several tech guys at the various manufacturers, and I'm comfortable with the products I'm using in my cars and boats, to suit the way I run my machinery. Tight tolerance European machinery benefits from a 5W30 or 0W30, but I’d never ever consider using that in a big loose American V8. The Mobil-1 15W50 I use in my Commander has performed well, and I suspect a 20W50 Amsoil would do even better, as Amsoil seems to win every head to head test I've seen. The Mobil 15W50 runs the same as a straight 50-weight oil would when it was hot, which provides some benefits for an engine that has some wear on it. Since this is an engineered product that ALSO has incredible cold flow, something like -50 degrees, it’s not the same as a straight 50W oil when hot, as the flow is vastly superior.
I found it particularly interesting that piston aircraft use a mix, part synthetic for the benefits, and part mineral oil, the latter helping reduce “grey point” problems due to the TEL (lead) in av-gas. I understand some pure synthetics have a tough time dealing with the lead buildup (turns to slime), and therefore they use a blend. In boats or cars we don't have this problem because lead has been outlawed a long time ago for cars and boats.
As a side note, here is an exerpt from the AeroShell Book:
“AeroShell Oil W 15W50 is superior to single grade oils in almost every application. It offers easier starting, better lubrication after start-up, reduced wear, reduced corrosion and rusting, and improved cleanliness, with oil pressures and temperatures equal to that of single grade SAE 50 oils at fully warmed up conditions.”
The AeroShell book continues:
“The anti-corrosion additive system is designed to prevent rust or corrosion in all types of aircraft piston engines. In comparative testing of camshaft rusting under high humidity conditions (boaters take note), AeroShell Oil W 15W-50 was almost entirely rust free while other camshafts conditioned on other oils showed sometimes heavy rusting on cam lobes and bearing surfaces.”
What does this mean for boaters? ANSWER: there may be something to the marine specific oil being marketed by people like AMSOIL. Should we use AeroShell in our boats or cars, ABSOLUTELY NOT.
If you want to know why, better read the AeroShell book, as there are plenty of reasons why this aviation-specific oil is not suitable for cars and boats. The info here is presented only to illustrate how far oil engineering has come, and how specific products deal with specific problems.
Of interest, AeroShell also has a “preservation oil” for aircraft that sit around long enough for the oil to absorb water. They contend that when this happens, the water forms a paste and it tends to greatly increase wear in an engine, cam lobes in particular. This gives even more reason why it may be good to use a marine-specific engineered product like AMSOIL marine in our boats.
Anyone interested in reading the AeroShell book, or their tech papers, check out
http://www.shell.com/aviation , it’s not directly applicable to marine use, but it’s a very good read and there are lots of interesting facts
Now here’s my top recommendation for marine use, small or big block:
All of the Marine recommendations from Amsoil can be found here
http://www.amsoil.com/products/marine/index.aspx
SAE 20W-50 Synthetic High Performance Motor Oil
Formulated for use in both gasoline and diesel engines. Offers multi-functionality and excellent wear protection. Ideal for applications where the extra protection of a higher viscosity oil is desired. Excellent for motor homes and older vehicles, as well as most types of modern equipment. Performance specifications include: API SL, CF & CI-4+
PRODUCT DESCRIPTION
AMSOIL High Performance Synthetic 20W-50 Motor Oil is specially formulated to provide superior protection and performance in the most demanding applications. It provides a wide range of protection in all four-cycle gasoline and diesel engines, including pickups, RVs, cars and off-highway vehicles and is ideal for use in high-stress vehicles subject to stop-and-go driving, short trips, high temperatures, frequent trailer pulling and off-road use.
Resists High Temperature Vaporization
Conventional motor oils tend to "boil off" in high temperatures, losing up to 25 percent of their original weight. These vaporized oils circulate poorly, reduce fuel efficiency and contribute to excessive emissions and engine wear. AMSOIL High Performance Synthetic 20W-50 Motor Oil resists vaporization. In fact, according to the NOACK Volatility Test, which measures the weight loss of an oil due to evaporation, AMSOIL Synthetic 20W-50 only loses 6.0 percent of its weight in high temperature service, surpassing rigorous European standards set at 13 percent weight loss in high temperature testing. The superior vaporization resistance of AMSOIL Synthetic 20W-50 keeps engine wear, oil consumption and emissions to a minimum, while keeping oil circulation efficient and fuel economy high.
Resists Oxidation and Thermal Breakdown
Conventional oils oxidize in high operating temperatures, producing sludge and deposit build-up that contribute to corrosion, increased engine wear and decreased fuel economy. AMSOIL High Performance Synthetic 20W-50 Motor Oil resists oil breakdown, maintaining its cooling and lubricating properties and providing extended drain intervals. It continues to provide maximum protection at temperatures that oxidize conventional oils. The advanced heat transfer capabilities and high lubricity of AMSOIL 20W-50 Motor Oil keep engines running in their optimum temperature range for top performance and long life.
Provides High Shear Stability
AMSOIL Synthetic 20W-50 Motor Oil surpasses the North American SAE and European ACEA oil specifications for high temperature/high shear (HTHS) viscosity. It retains its viscosity at temperatures and loads that cause conventional oils to shear back to a lower viscosity. AMSOIL 20W-50 Motor Oil maintains an extremely protective viscosity of 4.9 cP at 302°F (150°C) in the ASTM D 4683 High Temperature/High Shear Test, significantly exceeding test limits.
Provides Low Temperature Protection
AMSOIL Synthetic 20W-50 Motor Oil maintains outstanding low temperature fluidity, ensuring easy engine cranking for quick starts. During sub-zero temperatures, it flows to all parts of the engine much quicker than conventional petroleum 20W-50 oils, greatly reducing the rate of wear and increasing engine life.
Resists Deposit Formation
AMSOIL Synthetic 20W-50 Motor Oil is highly resistant to oxidation, running significantly cleaner than conventional motor oils. AMSOIL 20W-50 has a superior detergent/dispersant additive package that, when tested after tens of thousands of miles of use in the crankcase, still exhibits outstanding deposit control.
Inhibits Rust and Corrosion
AMSOIL Synthetic 20W-50 Motor Oil contains special rust and corrosion inhibitors to protect iron parts, as well as copper, lead and aluminum bearing materials.
Provides Extended Drain Intervals
AMSOIL Synthetic 20W-50 Motor Oil features a superior synthetic composition and advanced performance additives, performing much longer than competing conventional and synthetic oils.
APPLICATIONS
AMSOIL High Performance Synthetic 20W-50 Motor Oil may be used in gasoline or diesel engines requiring oils meeting the following specifications.
• API SL/CF & CI-4+
• ACEA A3, 83, E2, E3, E5
• Chrysler MS 8809A
• Cummins CES 20071, 20072, 20076, 20077
• Ford ESR M2C 179A
• Daimler Chrysler 228.3, 229.1
• Mack EO-L, EO-M, EO-M+
• Volvo VDS, VDS-2
• Allison C-3, C-4
• Caterpillar TO-2, TO-3
• JASO-MA
MIXING AMSOIL
AMSOIL High Performance Synthetic 20W-50 Motor Oil is compatible with conventional petroleum oils; however, mixing AMSOIL 20W-50 with a conventional oil will shorten the drain period of AMSOIL 20W-50. Engine oil additives or after-market products are not recommended for use with AMSOIL 20W-50.
SERVICE LIFE
In personal cars and light-duty trucks with nonturbocharged gasoline engines, change oil at three times the engine manufacturer's recommended drain interval or one year, whichever comes first.
In turbocharged gasoline engines, change oil at two times the engine manufacturer's recommended drain interval or six months, whichever comes first.
In high-performance and racing engines, change oil at intervals specified by used oil analysis.
In light-duty and non-turbocharged diesel engines, change oil at two or more times the engine manufacturer's recommended drain intervals if the findings of used oil analysis support those drain intervals or six months, whichever comes first.
In heavy-duty and turbocharged diesel engines, change oil at two or more times the engine manufacturer's recommended drain intervals if the findings of used oil analysis support those drain intervals or six months, whichever comes first.
In marine craft and occasionally used gasoline engines, change oil at three times the engine manufacturer's recommended drain interval or one year, whichever comes first.
In fleet vehicles and industrial gasoline engines, change oil at two times the engine manufacturer's recommended drain interval or six months, whichever comes first.
If the vehicle is equipped with an AMSOIL Oil Filter, the filter should be changed at 12,500-mile or six-month intervals (whichever comes first) in gasoline engines and 7000-mile or six-month intervals (whichever comes first) in diesel engines. Non-AMSOIL oil filters should be changed at the engine manufacturer's recommended filter change interval.
TYPICAL PHYSICAL PROPERTIES
AMSOIL High Performance Synthetic 20W-50 Motor Oil
Kinematic Viscosity @ 100°C, cSt (ASTM D-445) 18.1
Kinematic Viscosity @ 40°C, cSt (ASTM D-445) 126
Viscosity Index (ASTM D-2270) 161
CCS Viscosity @ -20°C, cP (ASTM D 2602) 3550
Pour Point °C (°F) (ASTM D 97) -38 (-35)
Flash Point °C (°F) (ASTM D 92) 236 (457)
High Temperature/High Shear @ 150°C and 1.0 X 106 s-1, cP (ASTM D 4683), cP 4.9
Four Ball Wear Test (ASTM D 4172 @ 40 kgf, 150°C, 1800 rpm, 1 hour, Scar in mm) 0.39
Noack Volatility, % weight loss (g/100g) (DIN 51581) 6.0
Total Base Number >12.0
Here’s the direct link for anyone wanting more information, or to order the product. In case anyone wants to know, I’m not in the “oil selling business”, I’m just an enthusiast.
http://www.amsoil.com/storefront/aro.aspx
What about Mobil-1 15W50? I still think that is a fantastic product, which I personally believe is far superior to the mineral oil alternatives. My 427s start easily, oil pressure is always very good, and consumption is nil. Knowing I have that extra margin of protection in the event I run hard with those big loose bearings, or overheat when an impeller goes out, just gives an added benefit I don't think I can get with the dinosaur oil. Anyone interested in switching over to synthetic, please don't take my word, call the tech department for the manufacturer of your choice and ask them. All I can do is offer what works for me. Do I think the Amsoil 20W50 marine oil is better? Yes. UPDATE: I now see Mobil-1 15W50 is ALSO offered in an EXTENDED PERFORMANCE version, and this is the one we'll need to be using in our boats if we choose Mobil-1 (it has 50% more anti wear additives and is recommended for severe use).
Would I use synthetic oil in a vintage speedboat that shares motor oil with the transmission? No. Would I use synthetic in a vintage speedboat that used ATF in the transmission, hmmmm, it would be very tempting, and probably yes.
Sincerely, and all the best,
Paul