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Discussion Starter #1
I really want to do right by my Bullitt as you may have noticed by some of the minor type questions I've asked such as what type of gas do you prefere. This forum has helped alot. Regarding oil changes I notice alot of post regarding differnet types of oil. My question is do most of you do your own oil changes? In my younger days I did it myself and for several years now have paid to have it done. I'm thinking about doing it myself again as I will be able to control the oil I use. I'm thing about some type of 5w20 SYNTHETIC. (The last oil change I got, I asked for 5w20 and once they drained the oil they couldn't locate the 5w20 they told me they carried....I ended up with 5w30 instead.) errrrrrrr!
 

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I would use 5w30 synthetic anyway. I was told by a good source that Ford may be stopping its recommendation of 5w20 in favor of 5w30 again. The only reason 5w20 was initially ecommended was for fuel economy and cleaner emisions I beleive. Me personally I use Mobile 1 5w30 synthetic
 

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I would use 5w30 synthetic anyway. I was told by a good source that Ford may be stopping its recommendation of 5w20 in favor of 5w30 again. The only reason 5w20 was initially recommended was for fuel economy and cleaner emisions I beleive. Me personally I use Mobile 1 5w30 synthetic
 

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sorry for the duplicate
 

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Discussion Starter #5
I saw somewhere where they stasted the bearing clearence was tighter now....wondered if that made a difference in oil weight...thanks for you response...Do you change it youself? How often do you need to change syntheic?
 

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Amsoil 5W20 arrived today, and will be going in my car in just a couple of short hours. Someone at Corral.net posted a link about the 5w20 spec awhile ago, and the implication was that the 5w20 spec defines properties other than just viscosity such that there shouldn't be any reason to think that 5w20 is incapable of protecting your engine well just because it is thinner.

Hey, 1302, I just went to the oil additives thread to copy/paste this link, but I see you already found it. ( http://www.mr2.com/TEXT/synth_oil.txt ) In this article it describes reasons why thinner oil is always better except for film strength and vaporization issues inherent in petroleum oils. I'm not qualified to vouch for the validity of every conclusion drawn in this article. However, I did read it thoroughly, and all of their logic makes sense to me. I was originally thinking "I don't care what ford says, no way I'm trusting oil that thin." The corral.net post more or less changed my mind. This snippet, from the article above, cinched it. Yes, it's really about synthetics, but it gets into the viscosity Q as well. I'm not preaching to use less than what Ford says, of course, but this removed any doubt I had about using 5W20. If the send me something changing the spec, I'll change what I use.

Joe

*** Quote from link above***


"Film strength" refers to the amount of pressure required to force out a film of oil from between two pieces of flat metal. The higher the film strength, the more protection is provided to such parts as piston rings, timing chain, cams, lifters, and rocker arms...wherever the lubricant is
not under oil-system pressure. Synthetics routinely exhibit a nominal film strength of well over 3,000 psi, while petroleum oils average somewhat less than 500 psi. The result is more lubricant protection between moving parts with synthetics.

Viscosity is a crucial consideration when improvements in fuel economy are desired. It stands to reason that the freer and engine turns, the less fuel it will require to accomplish a given amount of work. Studies have demonstrated conclusively that engine drag is directly related to
the viscosity of the motor oil. Generally speaking, the lower the viscosity, the better the fuel economy of the engine. In formulating lower-viscosity oils, it has become clear that synthetics are the base
stock of choice. This is because it is possible to produce a synthetic oil of a given low viscosity without incurring the excessive oil consumption (due to evaporation) and resultant thickening of the same low-viscosity petroleum oil. Indeed, the U.S. Department of Energy in its pamphlet entitled "An assessment Of The Effects Of Engine Lube Oils On Fuel Economy", states: "It is evident that low-viscosity oils will help minimize engine friction losses in the prevalent hydrodynamic
region and thereby achieve better fuel economy. In addition, such oils help to reduce friction during ambient (cold) start by increasing the oil flow rate to critical engine parts. However, low viscosity engine
oils, blended from conventional petroleum base stocks, may have problems with high oil consumption and engine wear. There is also the possibility of decreased catalytic-converter life and efficiency due to
the increased levels of phosphorus in the exhaust gas from the oil additives. *One solution is to mix some synthetic oil with the mineral (petroleum) oil, or use a synthetic base stock entirely*"(end of quote).
This low viscosity, low-volatility character of synthetics has become increasingly important because many automobile manufacturers are now recommending lighter-weight (chiefly 5W-30) oils for use in their
products, and because the trend toward smaller engines creates substantially more heat and stress on the oil used. In these smaller, high-output powerplants, enough heat is generated to cause a lighter petroleum lubricant to evaporate and significantly increase viscosity within weeks of its introduction into the crankcase. High temperature stability, as well as oxidation-resistance, is of absolutely paramount importance when it comes to turbocharged engines. Because it must both lubricate *and cool* the turbo unit, the oil MUST be specifically formulated to withstand the turbo's extremely high operating temperatures. Oil film temperatures often exceed 450F in the turbo unit during operation, and can surpass 650F(!!!) during a short period immediately following engine shutdown...both figures far exceeding the thermal limits of petroleum oil. Synthetics, with their capacity to
maintain proper (low) viscosity and lubricity under these high heat and stress conditions, and with their natural resistance to oxidation, have risen to the fore. It is also important to note that the
high-temperature-stability properties of synthetics are *designed primarily into the base-stock oil itself*, rather than being achieved primarily with additives. The advantage with approach is twofold: (1)
Additives, which may account for as much as 25% of the volume of a can of premium petroleum oil, by themselves have little or no lubricating properties per se. Thus the more the additive content in an oil, the
less lubrication is available to the engine; and (2) Most additives tend to volatilize (evaporate) and deteriorate with heat and age and use, so that the overall effectiveness of the lubricant itself is significantly diminished within only a few thousand miles of driving.

It is also important to note that, contrary to what many take for granted, higher viscosity in and of itself does not translate into better engine protection. Extensive testing has shown the opposite to be in fact true. As long as a lower-viscosity oil is formulated to resist
evaporation and provide high film strength, this lighter oil will actually deliver more complete protection to the engine parts, since its more rapid circulation delivers both better lubrication per se, and far
better cooling characteristics...a critical advantage, given that oil flow furnishes up to 30% of an engine cooling requirements. Prior to the introduction of synthetics, however, the problem of evaporation (and
the resultant thickening of the remaining oil) was addressed primarily by increasing viscosity. In short, don't be concerned with the relatively lower viscosity ratings of some synthetics. Syn lubes are a
whole new ball game.



***End Quote***


<font size=-1>[ This Message was edited by: DHG-1934 on 2001-08-09 11:18 ]</font>
 

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That’s an interesting quote. Does anyone know what film strength is sufficient for good protection? Just going by those numbers leaves you feeling like regular oil is totally inferior. I hope that’s not the case as I just stocked up on Valvoline AC 5W-20, two cases of it!
 

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Discussion Starter #8
Yes I saw that link....very good info...sound like synthetic is the way to go for exceptional protection/performance....One more question...In the parts store I saw 0w30...What's up with that? What about a synthetic 0w?
 
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