โApr-30-2015 11:25 AM
โMay-03-2015 06:33 PM
โMay-03-2015 06:22 PM
Wes Tausend wrote:427435 wrote:
A 5w-20 oil is no thinner at, say 0 degrees, than a 5w-40 oil. They both meet the viscosity requirements for a 5w oil at cold temps. And a 5w-40 oil is far thinner at operating temp than either 5w-20 or 5w-40 is at start up temps.
The person that said the 5w-20 oils are for improved mpg is spot on.
True about the 5w's being about the same cold, cold pouring no different. Not so with 10w30 etc.
But one must rethink about the so called 20 wt mpg factor. Since the 5w20 oil is thinner than the 5w40 at high temps, it flows(leaks away) faster. The pre-set pump torsional load force remains about the same (30-40# oil bypass) and more hot 20 weight is ultimately pumped through bearings in volume, than hot 40 weight. Basically the comparable hp parasitic drag of pumping either oil ends up about the same when hot, so the "claimed marketing" mpg gain of 20 becomes basically moot.
The Ford Triton engines pressurize the RH cam tensioner only after the oil has traveled from the front pump all the way to the rear of the engine, up to the RH head and forward all the way to the RH tensioner piston. The revised 20 weight oil better maintains more even pressure over this long passage than heavier oil. Oil pressure over lengthy passageways drops just like long, small garden hoses drop sprinkler pressure furthest from the supply. Ford has had some minor issues with the RH cam and RH tensioner over this long oiling path and 5w20 helps solve it. (The V-10 is longest of all.) Of course they are not going to advertise this.
I haven't seen it done, but I imagine installing a custom direct oil line, pump-to-the-front of the RH cam, would be a good performance durability mod. The LH head already oils this way. With no distributor shaft cam drive, the Triton oil pump is totally forward, keyed on the crank snout right in front of the 1st main bulkhead, not set back (centered-like) nearer the 2nd main web like older Ford engine designs, or 3rd web like early GM.
Wes
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โMay-03-2015 06:05 PM
Ductape wrote:
CAFE does not apply to vehicles in this weight class.
Interesting how some prefer the advice of random strangers to reading the manual.
Not to say there are no technically sophisticated enthusiast groups, but pages here yield nothing but anecdotes and opinions. BITOG is the place to go if you have a serious question on this subject.
โMay-03-2015 03:57 PM
โMay-03-2015 03:36 PM
โMay-03-2015 10:24 AM
Ductape wrote:Thats not what I'm reading. Aren't we talking about 8500lb and less ?
CAFE does not apply to vehicles in this weight class.
Interesting how some prefer the advice of random strangers to reading the manual.
Not to say there are no technically sophisticated enthusiast groups, but pages here yield nothing but anecdotes and opinions. BITOG is the place to go if you have a serious question on this subject.
โMay-03-2015 07:23 AM
โMay-03-2015 05:23 AM
Desert Captain wrote:
"Maybe in cold weather (winter), but in the summer when the oil is hot and as thin as water that protection can break down."
Seriously? "thin as water"? :h
This might have been an issue 50 years ago (remember back when a 3,000 mile oil change interval was actually recommended?), but with today's technology it's not. Oil gets hot regardless of the weather. The engineers at Ford recommend (actually they insist on), the 5W20 because it is the best oil for that particular engine (with its high RPM - close tolerance design).
:C
โMay-03-2015 05:00 AM
โMay-03-2015 12:34 AM
427435 wrote:
A 5w-20 oil is no thinner at, say 0 degrees, than a 5w-40 oil. They both meet the viscosity requirements for a 5w oil at cold temps. And a 5w-40 oil is far thinner at operating temp than either 5w-20 or 5w-40 is at start up temps.
The person that said the 5w-20 oils are for improved mpg is spot on.
โMay-02-2015 06:39 PM
โMay-02-2015 05:36 PM
โMay-02-2015 05:16 PM
Oldme wrote:I talked to the dealer about this seemingly exceptionally thin oil a few years back and he said it actually had to do with MPG. Obviously thicker oil requires more power to turn the engine, and he said that Ford as a company needed to hit an aggregate MPG number that because of their SUV and truck biz, was difficult. This thinner than what we all grew up with oil, he says does actually help.
My 2000 Ford V-10 calls for 5W-20
โMay-02-2015 04:25 PM
โMay-02-2015 04:09 PM
Wes Tausend wrote:
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Use 5w20. The thicker oils may not hurt the engine too much ordinarily, but they have a delayed circulation time in cool weather. This can cause lack of lube on overhead cam engines and damage camshafts and valve train.
It also turns out that the greatest benefit of pressurized oil in engines has been its ability to cool bearings. This, of course, takes a high flow rate to be most effective.
There is old wives tales still circulating around how thick oil can cushion bearings. Any modern day bearings that need "cushioning" are basically shot, usually galled by overheating, since the old, slow thick oils often failed at proper cooling. A bonus, fast flowing oil lasts longer now that it is not overheated by exposure lag under high heat stress. Oil thickens from heat as it ages and does not do as good a job cooling bearings. This thickening is one of the reasons automatic transmissions need frequent replacement lube, especially after abuse. Synthetic oils led the way to oils and blends that now resist thinkening.
Some of this knowledge became evident when it was noted how well automatic transmissions avoided wear with thin oils and how sensitive they were to cooling. This is opposed to manual transmissions that used to often use 90 weight gear lube, many of which now also use thinner oils.
Wes
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