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#16
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Quote:
Why do you think this?
__________________
2006 E350 w/ 155k miles (Daily Driver) Previous: 1993 300E 3.2L Sedan w/ close to about 300k miles 2003 E500 Brilliant Silver (Had 217k miles when totalled!) 1989 300E with 289,000 miles (had for <1 yr while in HI) 03 CLK 500 cabrio (Mom's) 2006 C230k (Dad's) 1999 S420 (Mom's/Dad's) 2000 C230k Sport sedans 2001 CLK320 Cabrio (Mom's) 1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!) |
#17
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The only caution I would add to the use of multi-weight is try not to cover a wide range of parameters with one oil. The buffers/medium that enable one oil to behave well from low to high temperature extremes does not contribute to lubrication themselves. Also, this is the substance that is first to 'coke-out' when exreme temperatures are encountered. In other words, instead of using 0-50w, try 10-30w or 20-40w. Most aircraft oils encounter some pretty high temps since the engines are air cooled and find themselves in some pretty tight cowlings so a great deal of pilots prefer a straight single weight, such as 80 in the northern climes and 100 in the south. This lessens the chance of oil breakdown. FWIW.
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#18
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Viscosity Is Relative, Not Static...
First, read your owner's manual as regards recommendations for viscosity. The viscosity of a multigrade oil is determined by the climate you operate in, not just the year and model of car. For instance, I live in California, and for my cars, I need to use a higher viscosity rated oil, like 15W50. If I lived in a cooler climate, I could use 10W30, or even a 0W40. The "W" stands for "Winter", not "Weight"...
Some extremists believe that a 0W40 will work better for them even in California, because they think that the oil is at 0 viscosity when the car is started. That would only be true if the ambient temperature were cold enough to cause the oil to flow at 0 viscosity. If the temperature were say, 56°F, wouldn't the oil actually be about 10, or 15 anyway due to the rise in temperature from where the oil would be flowing at 0 viscosity? I don't know that answer yet, but I'd like to, so I will try to find out just what the temperate spread is on a multigrade oil.
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"We drive into the future using only our rearview mirror." - Marshall McLuhan - Scott Longston Northern California Wine Country... "Turbos whistle, grapes wine..." |
#19
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The flow characteristics of a 10w-40 oil matches what a straight 10 would do in cold ambient temps as well as a straight 40 at the higher temps. And yes the w stands for winter but is referred to as weight (why, I don't know). I don't know why the 80 weight aircraft oil is actually referred to as 40 and the 100 as a 50, either. Perhaps there is a 'proof' involved in aviation.
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#20
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Longston, what dynamic behavior do you profess that oils possess?
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#21
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Yes, But...
What I mean is at what temperatures does the oil exhibit characteristics of increased viscosity, and to what degree?
For instance, 10W30 is at a viscosity of 10 between what two temperatures before the polymers that make up the viscosity improvers cause the 10 to shift to a 15, or a 20, and then to 25, or 30? And the numbers associated with aircraft oils are derived from the Mil. Spec., or Military Specification #. So, 30 weight, is actually Mil Spec. 1065, or commercial aviation # 65, while 40 weight is Mil Spec 1080, or commercial aviation # 80, 50 weight is Mil Spec 60, but commercial aviation # 100, and 60 weight is Mil Spec 1120, and commercial aviation # 120. Rememeber pilots, "proof" is never a safe thing in aviation. "12 hours from bottle to throttle" is a safe rule... Multi viscosity oils should never be referred to as 10-weight-40. This is a misnomer carried over from single weight oils that are referred to as "30-weight", or 40-weight. 10W30 is simply, 10-30...
__________________
"We drive into the future using only our rearview mirror." - Marshall McLuhan - Scott Longston Northern California Wine Country... "Turbos whistle, grapes wine..." |
#22
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Yeah!....what he said!
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#23
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longston
Are you of the opinion that multi-grade oils exhibit changes geometrically from the low end to high end of ambient temperatures as opposed to directly proportional?
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#24
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For all FSS cars:
The factory fill for 98's was pure dino oil. For 2001's the factory fill was switched to synth/dino blend. Sometime in 2001 the factory fill was switched to pure synth. The switch was made right after the "recommendation" to switch to synthetic oil. Kuan |
#25
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Hi Guys!
My W-140 92'300SEL runs on CHEMLUBE 10W-30 and is now running into 123K miles. Best oil I have ever experienced with the engine silky smooth. Comments from members who have tried CHEMLUBE! Try it and you will feel the difference. Happy Motoring. |
#26
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Quote:
Assuming you gathered some data and managed to get some points. At low temps, they will fit a straight line. At another temperature, they will fit yet another different straight line. Kuan |
#27
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Kuan, to what are you correlating the value of temperatures to plot yet a different function?
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#28
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Sorry, I thought we were talking viscosity here. Never mind me...
Kuan |
#29
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Oh, I thought you had something there I had not run across.
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#30
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So from what I read, I drew 2 conclusions
correct me if I am wrong For synth.. thick oils like 15-50 should be used in hot climate? while 10-30 or 5-30 should be used in cold climate? does that apply to the FSS cars...for 98-2000 models i mean |
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