Motor Oil 108 | FerrariChat

Motor Oil 108

Discussion in 'Technical Q&A' started by AEHaas, Nov 29, 2004.

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  1. AEHaas

    AEHaas Formula 3

    May 9, 2003
    1,458
    Osprey, Florida
    Full Name:
    Ali E. Haas
    Motor Oil 108
    Chapter Eight. Odds and ends.

    I have some stories that I collected. First, my architect drives a big SUV. He was running with Mobil 1 brand 15W-50. He changed it to Pennzoil Multigrade (mineral oil based, non-synthetic, cheap) 5W-20 at my suggestion. His gas mileage went from 10 to 13 MPG around town. What really impressed him the most was the “robust” increase in “get up and go.” He changed from a thick synthetic to a thin mineral oil. His venue is stop and go city traffic in Florida, mostly short trips. The oil just never got that hot to require a 50 weight oil. Short trips means that the oil temperature never gets up to the normal operating range. It was too thick on short trips and too thick when it did get up to temperature.

    The lower temperatures he was seeing occurred because of reduced friction and internal drag and higher oil flow.

    One of the members of the Ferrari Chat web site went from a 40 to a 30 weight oil in his Ferrari 355 for racing in Texas. He noticed a drop in temperature but no change in oil pressure. This may seem odd but really makes perfect sense. Since the 30 weight oil is thinner he got better flow and therefore better cooling. The oil was at a lower temperature so it was not as thin than it would have been at the previous higher temperature. Cooler engines last longer. Fact: The higher the temperature, the greater the wear, all other things being equal.

    People say that their old car manual says to use a 10W-40 so they would never think of using a 0W-40. Again, both are the same viscosity at normal engine operating temperature. The 0W-40 just does not thicken as much after you turn off your engine. There are now several cases when manuals for older cars have been updated to reflect this. My 550 Ferrari Maranello manual said to use 5W-40 yet the 575 manual says to use the 0W-40. The engines are the same except the 575 has more BHP. It has better acceleration and more top speed. The engines have the same tolerances.

    All manufacturers I have seen are specifying 0W-XX or 5W-XX oils now. Ferrari, Ford, Mercedes, Porsche, and others specify a 0W-XX oil to mention a few. These are appropriate for all engines of all ages of all levels of wear. This second number is the only thing that may change with an older, lose or worn engine. This can only be determined by experimentation. If you are using XW-50, go to a 0W-40. If your pressures are still too high go to a 0W-30 and so on.

    When I took delivery of my 575 Maranello I drove for 500 miles then changed the oil to 0W-30 Mobil 1. There were no changes in operating pressure or temperature. Starting the engine seemed faster though. I called up FNA and was told that all new Ferrari cars are delivered with 5W-30 Shell Helix Ultra. That is when I decided to try the 0W-20 Mobil 1. I could even go to a 10 weight oil as my pressures are still excessive while driving around town. I do not drive on the track.

    What about the break in period? For one thing you could just follow the cars manual and gradually break your engine in. Some cars like Ferrari and Lamborghini run engines and the cars for a period of time before you even take delivery. They often run up to full power. Some representatives at least from Ferrari hinted that the traditional break in period was not really needed, at least in their car.

    Most people who buy high powered cars that I have experienced will just get in there cars and step on the gas fully. They do not wait for the oil to warm up. Personally I would not mind running full BHP for short bursts during the break in period but I always fully warm up the engine first.

    Older engines may in fact benefit from thinner oil use. Over time permanent deposits of carbon and sludge build up in the engine oil ways. It is like a clogging of arteries in humans. We are now all on blood thinners. This is an area I specifically studied while a general surgeon resident at Chapel Hill.

    Thinner oils, and specifically synthetic products are better. Some people say their engines were “designed” to run on mineral based lubricates. This too is false. The synthetic of the same viscosity as the mineral oil you are now using will be an improvement. If you go from a mineral to an even thinner synthetic you may be better off still. The pressures go up in many older engines because of this “clogging” of the arteries. Most think this is good but is is really a lessening of flow and therefore accelerates engine wear even further.

    For those engines with excessive varnish and carbon buildup the engine oil additives of the detergent type may be of benefit. On the other hand you could just use a thin synthetic oil and change it every 200 miles for a while and end up with an even cleaner engine. With everything working properly you may actually need a thicker oil if that engine is overly worn. The thicker oil would be a disaster however, if the arteries were narrowed from deposits.

    Remember, the only difference between a 0W-40 and a 10W-40 is that the 0W-40 thickens less after you turn off your engine. It is still too thick in the morning at startup but not as thick as the 10W-40. Yet, they are still too thick to use until they both warm up to operating temperature at which point they have the save viscosity, around 13 to 14. Remember that the 0W-30, 10W-30 and straight 30 weight oils all have a viscosity of around 10 at normal engine operating temperatures.

    There is one more thing. A 20 weight oil is not half as thick as a 40 weight oil. The real scale is more like the oils having an absolute thickness of 108 and 114. Now it can be seen that the 40 weight oil is only around 10 percent thicker than the 20 weight oil. The difference is not that much at operation but at startup the difference is significant. Pressure / flow dynamics go along with this 10 percent figure. A 30 weight oil should be thought of as having an absolute viscosity of 110 and a 50 weight oil has an absolute viscosity of 120. I am talking about operating temperatures.

    I thought everyone knew that 90 percent of engine wear occurs during the startup period because oil is just too thick. One person thought it was good to have a thicker oil for startup since the parts shrink when cold and would otherwise “rattle.” Sure, your piston diameter will shrink on cooling but so will the diameter of your bore. The net result is about the same clearance hot and cold. This is not true for your valves. They lengthen when extremely hot. In the Murcielago they use shims instead of self adjusting valve tappets. You need to put a millimeter of clearance there so that after expansion the valve will not be held partly open when it is supposed to be closed.

    The manufacturers know what parts shrink or expand and the clearance changes that result. You do not have to worry about this. If it was that easy to design engines we would all be making them.

    I would like to go back to the worry that oil falls off the parts when a car is stored or sees long periods of inactivity. For the first oil change in my 575 Maranello I drained the Shell and put in 0W-30 Mobil 1. This was at 775 miles on the odometer. I drove the car home from work, put it on the lift and drained the transaxle and engine oils. I also opened and drained the oil cooler and took off every line that is in the oil system. I wanted to get every speck of the Shell oil out of there. You are not supposed to mix synthetic oils of different brands.

    The system takes 12 quarts with a “normal” oil change but took 15 quarts for this change. It all took about an hour. I then started the engine to check for leaks. The multitude of mechanical engine noises that followed nearly broke my eardrums for about 10 long seconds. Then it was suddenly very quiet. You could hear a pin drop. There was certainly the most possible amount of surface oil on all the internal parts as the engine was only off for an hour. But it was not until the oil circuit primed, filled then sent flow into all the parts that any lubrication was occurring. Hence all oil filters that are manufacturer certified have back flow limiters to keep the oil filter full even with the engine off.

    Here is an interesting tidbit of information. A 75W-90 gear oil has the same viscosity as a 10W-40 engine oil at 212 and 302 F. Once again, those numbers on that oil can are misleading and certainly add to the confusion I see among automotive enthusiasts.

    aehaas

    (just 2 more chapters to go before final exam)
     
  2. Mike C

    Mike C F1 Veteran
    Lifetime Rossa Owner

    Aug 3, 2002
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    Mike Charness
    Again, as previously discussed, the manufacturers themselves say this is not the case. Here is a quote from one of Shell's websites:

    Shell's Staff Research Engineer Stephen Miller says... "All grades of Shell oils, synthetic and conventional, can be mixed with no compatibility issues."

    Shell has also tested compatibility of products with our four major motor oil competitors. While we can't always be sure of what changes they may be making to their formulations, we currently are not aware of any compatibility issues.

    "It is certainly true that there are additive technologies and synthetics combinations available that could cause incompatibilities," Miller says. "But Shell does not use them, and I know that if that ever changed, we would be sure to keep everyone very well informed."


    Similar statements can be found at other manufacturers sites.
     
  3. AEHaas

    AEHaas Formula 3

    May 9, 2003
    1,458
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    Ali E. Haas
    Oils that are compatible may be mixed without untoward effects. The new ratings require oils to be compatible. All oils so labeled may be mixed.

    However, that does not mean the manufacturers want them mixed. It will dilute proprietary additives. The dilution of additives is one of the main reasons you need to change your oil.

    aehaas
     
  4. mk e

    mk e F1 World Champ

    Oct 31, 2003
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    Starting with emty oil lines was probably not a good idea. 10 seconds without oil seems like a very long time. When I have a system I know is empty, I unplug the injector harness and crank until there is some sign of pressure. Then plug the injectors back in and let it fire. I am also a big fan of pre-filling the oil filter before installing it to minimize the time to pressure, even though it is a bit messier to do.
     
  5. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
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    Franklin E. Parker
    AEHass, I cannot find Castrol Syntec 5w50 oil anywhere. Do you have to special order it?
     
  6. don_xvi

    don_xvi F1 Rookie

    Nov 1, 2003
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    hehe, with a top mounted oil filter I have actually poured oil down a funnel into the oil filter threaded adapter, screwed the filter on real fast and then started the engine up just as fast as I could scurry around to the seat! But I realized that was all pointless. But it felt good at the time! :)
     
  7. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
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    I found some 5w50 at Advance Auto during lunch today. $22.00 for a six bottle case.
     
  8. AEHaas

    AEHaas Formula 3

    May 9, 2003
    1,458
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    Ali E. Haas
    This is Castrol and other data. See if this works. The phone number and web addresses are here.

    aehaas
     
  9. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    17,913
    USA
    I'm curious...looking at the data on the Castrol Syntec 5w-50...it is very thick at 40 C...seems to act more like a 10w or 15w at colder temps, rather than a 5w...can you comment?
     
  10. AEHaas

    AEHaas Formula 3

    May 9, 2003
    1,458
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    Ali E. Haas
    That comes up in lesson 109. Just note that the 5W-50 is much less thickened at 40 C than the 20W-50. This is why I recommend this over other choices. It's better, less thick at startup. But still WAY too thick to use before you engine is warmed up.

    aehaas
     
  11. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
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    It would seem that unless the 50 weight is absolutely needed, that a 5w-40 or 0w-40 would be a much better choice.....
     
  12. don_xvi

    don_xvi F1 Rookie

    Nov 1, 2003
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    This is absolutely true!

    The only question is "what is required for the big number?" (And that's rhetorical at the moment.)
     
  13. mk e

    mk e F1 World Champ

    Oct 31, 2003
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    Yes. I think that the vast majority or what has been said here regarding oil is true, but I also think some of the conclusions/advise regarding low viscosity are a bit questionable.

    I’ve been following this and think maybe it is time to chime in….as a mechanical engineer who works on product design and development (medical products though, not cars).

    In the most general terms, you do want to run the lowest weight oil you can.…..and all car makers spend a lot of time deciding what that is and what to recommend. I don’t think second guessing the factory engineers is a wise move.

    If you are at the track or in other controlled conditions and can monitor engine and oil temperatures and pressure, maybe. On the street where conditions and operation change dramatically from day to day and “monitoring” is really just a glance at the gauges every 15-30 minutes, then no.

    Reducing the weight of the oil comes with a lot of risk and very little return. If the pressure drops there is a very very real chance the crankshaft will contact the main or rod bearing surface (it is supposed to ride on a film of oil) and the game is over, the engine is destroyed. It happens instantly, and there is no way to know just how close to the limit you are at any time or set of conditions, i.e. 40 psi is fine but 39.9 may not be.

    Running the oil the factory has recommended pretty much ensures you will not have a problem of any kind. Most of the time, and for some drivers all of the time, a thinner oil would work just fine. But honestly, when you stomp on the throttle do you really want to wonder? Is the couple hp you gain worth the wondering? To me it’s not.

    Running a 0w-50 instead of a 10w-50 in probably a good thing overall. The only drawback is that they could be (and probably are) getting the larger spread by putting in more additives, which means there is less room left for oil in your oil. Up until quite recently many racing oils were straight weight for just this reason. Synthetics are inherently more stable, so higher ranges are possible than with conventional oils. I guess for general street use, the newer wider spread oils are probably the way to go, but for the track, I am not convinced.

    I personally would never even consider dropping the upper number from what the manufacturer has recommended. Ever. JMO
     
  14. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
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    Franklin E. Parker
    Ferrari recommends Agip SINT2000 10w50 for my BB512i. However, 10w50 is no longer available from Agip nor any other company. So, I have been using Mobile1 15w50. Would I be better off using Castrol Syntec 5w50 instead?
     
  15. AEHaas

    AEHaas Formula 3

    May 9, 2003
    1,458
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    Ali E. Haas

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