Motor oil university 106

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FCD

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On chapter 6 of the motor oil university called "Personal preference" it says that No conventional Xx-w50 oils are reccomended because apparently they are all too thick at startup, does this refer to Straight 50 weight oils? 20w50 oils? , if it does refer to 20w50's for example this sounds pretty ridiculous to me since it seem to claim that they are too thick regardless of the application or anything else.
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i think in Florida due to all the Florida related questions in which case a 20w50 would probably be just fine to use during most of the year in the proper application ofcourse
 
It's a meme that 101 and a few other posters regurgitate.

The premise is that engines are built for "10" (that's in 101, and in spite of questioning the author he hasn't come out with any evidence to that end.)

The premise is also that at lower temperatures the oil is "too thick" to do it's job, and that the ideal lubricant must be "10" from the time the engine is started to the time that operating temperature.

That's incorrect, as in the cooler (warmup) temperatures before the additives kick in, viscosity is all you have to keep wear at bay (or some of the newer novel additives).

It's the reason that the industry standard wear test (sequence IVA, and soon to be replaced by IVB) hold the engine and oil at 65C or thereabouts, as that's where the most valvetrain wear occurs.

The designers of the test claim that the test has no discernable preference to viscosity...if 101 was correct, then the thinnest, highest VI oils MUST perform better than these "too thick" oils.

As to the author of 101, he could run SAE30, which has no "W" rating and not suffer the effects of "too thick" when cold.
 
101 is wrong on many things. anyway regarding what shannow said "It's the reason that the industry standard wear test (sequence IVA, and soon to be replaced by IVB) hold the engine and oil at 65C or thereabouts, as that's where the most valvetrain wear occurs."
So only wear at the valvetrain at the warm up phase is cause for concern? At this temp range 60 - 70C, wont affect bearings and rings ?
 
alcyon,
in order to be a standard, the results must be easily discerned and be repeatable...and be obtained in a reasonably short timeframe.

The the industry standard test uses cams and valvetrain rather than rings and bores, or shafts and bearings...it doesn't mean that only these items were.

I'm (presuming) that the ability to replace cams and valvetrains fairly quickly on an engine, while leaving the bottom end untouched makes the test a heap cheaper/quicker than a full tear-down.
 
Originally Posted By: FordCapriDriver
i think in Florida due to all the Florida related questions in which case a 20w50 would probably be just fine to use during most of the year in the proper application ofcourse




Isnt Florida kind of related to Spain? When I vacation there I sometimes hear Spanish accents and see French/Spanish type cities and landmark type objects. 20w is probably not going to be a problem in some vehicles above freezing temperatures. Below freezing, you probably want to have a 10w in the sump.
 
My Enzo Ferrari calls for the Shell Helix Ultra racing 10W-60 but I have used the Castrol Syntec European Formula 0W-30. This is different than the easy to find plain 0W-30 Syntec

as from my point of view? his idea work. baught a brand new car and used his concept ,never had issue with my car !
 
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yvon_la, wow to change a post between initial and edit...I nearly responded to the 10psi/1000RPM post...wouldn't I have looked silly.
 
the 10psi per 1000rpm thinghy seems unrealistic to me. if you rev say above 3000rpm, the heat in the oil will rise and the viscosity will go down, so will oil pressure, I bet with a 0W-20 he will achieve max oil pressure at 7000rpm,albeit only for a minute or less. If he keeps the revs at 7000rpm for a few minutes, I bet the oil pressure will start dropping drastically, with a drastic increase in oil temps.
 
10psi per 1000RPM was an old small block (chev, ford, chrysler) rule of thumb for "adequate" oil supply volume to get the job done.

It doesn't define, nor provide lubrication.

101 states that the pressure is lubrication, then later that it's the flow, not the pressure.

It's neither.

With an adequate volume of oil supplied, the bearings will lubricate themselves, and draw from that supply most adequately...thicker oil they suck less oil out, and the backpressure goes up.

Piston squirters rely on pressure/density to provide flow...more pressure, more flow, more cooling.

As to your premise that a few minutes at 7,000RPM will result in lots of oil heat, and viscosity drop, I concur.
 
Originally Posted By: FordCapriDriver
i think in Florida due to all the Florida related questions in which case a 20w50 would probably be just fine to use during most of the year in the proper application ofcourse


Rarely ever a need for such a thick oil... not sure but alot of cars in Florida run 0w20 and have no oil related issues.. so not sure what your point is. They can run a thick oil, but whats the point? This argument of thick vs thin could go on forever. You cant prove thin oil to cause issues and it is most recommended by manufacturers here, so prove how they are doing it for CAFE or for claiming better mileage? You would have a point if there were multiple engine failures due to the use of oil that is, "too thin". If thin works as good as thick, and the only benefit being you save gas money using thinner, wouldn't that mean thin is a better option?

I do see you said in the proper application.. which I agree with.. but not much applies for 20w50 oil, at least when it comes to automobiles.
 
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i agree with modern oil technology very few cars, even classics "need" a 20w50, i run it mostly to keep oil consumption down, my owner's manual specs 20w50 for hot climates but in the 70s a 20w50 would've likely quicly sheared to a 40wt due to fuel dilution and other things, my engine would probably run just fine on a quality 5w30 or 5w40 synthetic with all the right additives for an older engines like zddp etc...
 
Originally Posted By: alcyon
the 10psi per 1000rpm thinghy seems unrealistic to me.


It is exactly what a new-from-factory 1956-1996 Chevy smallblock v8 did, so it became "the rule." Its that simple.

Despite the fact that the majority of other engines (even other GM engines) don't act quite the same way.
 
Originally Posted By: 440Magnum
Originally Posted By: alcyon
the 10psi per 1000rpm thinghy seems unrealistic to me.


It is exactly what a new-from-factory 1956-1996 Chevy smallblock v8 did, so it became "the rule." Its that simple.

Despite the fact that the majority of other engines (even other GM engines) don't act quite the same way.



Bubba says: If it's good enough for a tree-fiddy it's good enough for any engine
 
Originally Posted By: Miller88
If a 20w-50 is too thick, a straight 50 (if such a thing is even available) is going to be way too thick.


Alot of oil companies make mono grade 50 and 60 weights. Pennzoil and Valvoline make them in their racing oils.
 
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