Synth 20w = Bullet proof

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When Ford started testing 20 weight oils, they found out that the 4.0 V-6 did not have enough volume to the cam chain area with a 20 weight. They therefore would not back-recommend 20 weight for these engines, even though it would have benefitted them to do so.

IIRC, Ford also made some changes to the later 5.0 V-8's to make the 20 weight compatible.
 
"...so what lubrication principle are they appealing to ?"

"One has to last 5 laps (or whatever) ..the other 500+ miles. Both are to provide lowest parasitic losses over the duration of use."

In short there is less wear with the thicker oil.
 
I'm guessing that 5W-20 weight oil is gonna become the industry standard as more and more car manufacturers need to squeeze every drop of MPG outta their cars made.

Earlier I had asked this same question for my 01' Durango as it needs 5w30 weight and unfortunately didn't get a straight answer. Reqardless it's probably fine but it doesn't hurt to ask.

Durango
 
The oil weight selection should be made based mostly on bearing clearance. A lot of the newer cars run about .0015" on the mains and rods. 20 weight is perfect for that. I just finished a high output twin turbo engine for my stealth. I ran about.0028" clearance for a bigger wedge. Also the oil flows through two turbos. To top it off i live in arizona and it's summertime and my oil temp rarely goes below 100 after 48 hours of not driving the car. After breakin with 20w40 dino oil i will be running straight weight 40 synthetic. Straight weight oil has much better chance of staying the weight listed on the jug than a multi viscosity, and living in the desert, i don't really have a "cold" startup.
 
Originally Posted By: 1sttruck
"...so what lubrication principle are they appealing to ?"

"One has to last 5 laps (or whatever) ..the other 500+ miles. Both are to provide lowest parasitic losses over the duration of use."

In short there is less wear with the thicker oil.


I don't see how you can say. There's longer life with a thicker oil. 500+ miles vs 5-10 miles. One would assume that there are process variables that would make the lighter oil unacceptable for 500+ miles of use. The heavier oil is buffered to endure those insults over a much longer duration.


How do you determine the difference between your view and mine? Every oil/engine/usage composite has a decay curve (only upset by something like M1 0w-40 with it's "refried beans" applause for how it decays by design). The service duration and the starting condition of the oil is spec'd to endure that entire composite with various levels of buffering. An oil with a 10 mile duration of use can be lighter with NO ABNORMAL WEAR ..but would fail over 25 miles of usage under the same process variable. It's the same thing if you had 10% fuel dilution with a 5w-40. It's not going to provide the same protection over the same span as one subjected to 1% fuel dilution.
 
Well there is certainly a strong correlation between HTHS and wear, and HTHS correlates to viscosity when all else is equal. The HTHS/wear correlation is mentioned in many studies and technical papers as a starting point - it is taken for granted.

But of course there are lots of complications, like cold flow and of course the design of the oiling system. But yes, all else equal, within the range of appropriate viscosities, thicker would tend to be better for wear.
 
"I don't see how you can say. There's longer life with a thicker oil. 500+ miles vs 5-10 miles."

We're talking about a basic principle of lubrication, but instead it seems to be a fundamental that is ignored, even denied. It's almost like evolution in other discussions. If this principle does not apply then why usn't everyone using 5wt oils in their passenger vehicles, as they would get better fule mileage ? In this case fuel dilution isn't a problem.

Shell and Ferrari were doing the same thing trying to get good qualifying times, get practice inm race, and get engines to last more than one race in F1. They determined that they had a wear budget and used thicker oils for practice in order to avoid using up too much of the wear budget. NASCAR could use thinner oils and change them during the race during pit stops, but this doesn't seem to common prcatice, as they evidently they need the thicker oils to minimize wear.
 
I have an '09 Corolla and it asks for 0w20/5w20 on the cap and owners manual. Funny thing is my brother has an '07 and it says 0w30/5w30 and its the same engine. I know its for CAFE and the TSB that toyota came out in March 29, 2006 states many times it is for fuel economy and for the environment, and also mentions superior engine protection, but then in the next paragraph it says: "The recommended viscosity grade for this oil differs according to vehicle model. use the recommended grade specified on the oil filler cap or in the repair manual or owners manual for each vehicle.."

The '08 engine is on the list to use the 20wt oil, but the filler cap, manual all say 30wt.

Due to this information, I have decided the difference between good quality versions of the two oils is so small that I have elected to use the 30wt in the '09 Corolla. The engine was quieter, and produced no measureable mpg loss.

Are the european cars on the 20wt diet, from the models I looked at they are still on the 40wts, and fuel is so expensive compared to North America you'd think they would be all for eeking out that extra mpg. Why?
 
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Quote:
We're talking about a basic principle of lubrication, but instead it seems to be a fundamental that is ignored, even denied.


Not at all.

Quote:
If this principle does not apply then why usn't everyone using 5wt oils in their passenger vehicles, as they would get better fule mileage ?


Because even if you designed an engine that could run with nominal wear, indefinitely, on 5 weight oil, you cannot create a 5 weight oil without volatility issues or one that can sustain the process variable for any length of service for sensible use.


Take your big lumbering diesel truck with your ROBUST 40 weight mega strong arm superior viscosity oil. Elevate your oil temps to 275F hauling your favorite toy over your mountain..or whatever, and it's no longer the 850lb gorilla that you started with. You've got a wimpy 20 weight (or whatever). Your process variable requires that buffering to manage your service. Yet you're happy as a clam because you're operating with a high visc oil ..but not at the moment.

So, what you're really boasting about is how "buffered" your oil is for the process variable.

So, now I just design things so that the process variables never insult the oil to alter its state too much ..or I merely leave the oil in there for the shortest of time that it's viable for ..and there's no effective difference.
 
"So, now I just design things so that the process variables never insult the oil to alter its state too much ..or I merely leave the oil in there for the shortest of time that it's viable for ..and there's no effective difference."

In the case of NASCAR or Ferrari in F1, the RPMs, loads, and temps will be constant for each in qualifying, practice, and racing, the only difference is how much wear they're willing to tolerate. The use thinner oils for higher output and thicker oils for less wear.
 
Originally Posted By: 1sttruck
"So, now I just design things so that the process variables never insult the oil to alter its state too much ..or I merely leave the oil in there for the shortest of time that it's viable for ..and there's no effective difference."

In the case of NASCAR or Ferrari in F1, the RPMs, loads, and temps will be constant for each in qualifying, practice, and racing, the only difference is how much wear they're willing to tolerate. The use thinner oils for higher output and thicker oils for less wear.



..and they change the oil in a 500+ mile race?

You're dodging the point. The oil that they use during the race has a "life curve". I'm sure that it's not in the same condition that it started out at the beginning of the race. The engine builder would manage the engine wear rate to last just beyond the end of the race ..or the output level to just push the fractional limits of tolerance over the entire 500+ miles.

That oil must perform for all of those miles. If he could stop the race and replace the 0w0 oil every 5 laps ..there's no reason to think that the engine wouldn't make it the entire 500 miles.

..or do you know what 500+ mile 20 weight looks like at the end of the race??

You're focusing on wear that's inherent to the environment and back rationalizing it to assert that there's some "damage" caused by the oil.
 
Let me offer you this to ponder...

If they ran 70 weights ..and accepted the loss in available horsepower ..would the same engine, with the same ultra fine "at the edge of the envelope" setup, make it to 800+ miles ...24 hours at Le Mans?

In 1970-something, (IIRC) Ford engineers got the DOHC 427 to push over 700hp. They detuned it to 500+/- to make 24hours.

Are you saying that if they could have found 70 weight, they could have left it peaked ..or was there another reason for the detuning?
 
"You're dodging the point. The oil that they use during the race has a "life curve". I'm sure that it's not in the same condition that it started out at the beginning of the race."

1. Shell used a light oil in the Ferrari for qualifying, a tradeoff of wear for speed.

2. Shell useda heavier oil for racing, in order to get the engine to last. The same engine used in qualifying, same output, same rpm, same load, same temps.

3. Shell used an even heavier oil for practice, in order to minimize wear. Same engine, same loads, same temps, same rpm.

Why did Shell use the heaviest oil in practice ? What lubrication principle were they appealing to ?

Hint - they're running at the low end of acceptable viscosity for the engine, they're willing to accept some wear in order to get as much power out of the negine for qualifying and racing, but since the engines had to last more than one race they had to munimize wear when possible. Bigger hint - they figured out that they could minimize wear during practice by using a heavier oil.
 
Originally Posted By: Gary Allan
..or was there another reason for the detuning?

Just a thought but probably a combination of inter-related variables. In racing, engine wear rate is the square of rpm, even more when physical limits are approached, and power goes with rpm - they probably were at many mechanical limits - valve spring fatigue, rod bolt stretch, pistons on the verge of melting, destructive detonation, who knows what.

Only some oil related and possibly none oil related.
 
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Originally Posted By: Gary Allan
Let me offer you this to ponder...

If they ran 70 weights ..and accepted the loss in available horsepower ..would the same engine, with the same ultra fine "at the edge of the envelope" setup, make it to 800+ miles ...24 hours at Le Mans?

In 1970-something, (IIRC) Ford engineers got the DOHC 427 to push over 700hp. They detuned it to 500+/- to make 24hours.

Are you saying that if they could have found 70 weight, they could have left it peaked ..or was there another reason for the detuning?



I THINK you are thinking of the 427 SOHC...........
 
crazy2.gif


I don't know how it's possible to single out just viscosity as a factor for wear when so many other things matter such as engine designs etc.? Never really understood the hangup with viscosity.
 
Originally Posted By: OVERK1LL
Originally Posted By: Gary Allan
Let me offer you this to ponder...

If they ran 70 weights ..and accepted the loss in available horsepower ..would the same engine, with the same ultra fine "at the edge of the envelope" setup, make it to 800+ miles ...24 hours at Le Mans?

In 1970-something, (IIRC) Ford engineers got the DOHC 427 to push over 700hp. They detuned it to 500+/- to make 24hours.

Are you saying that if they could have found 70 weight, they could have left it peaked ..or was there another reason for the detuning?



I THINK you are thinking of the 427 SOHC...........


When I was little I always wondered what made the 427 "sock" (as it was pronounced) different from the rest. Now I can never mistake it for a DOHC thanks to that mispronunciation.
 
Originally Posted By: BuickGN
Originally Posted By: OVERK1LL
Originally Posted By: Gary Allan
Let me offer you this to ponder...

If they ran 70 weights ..and accepted the loss in available horsepower ..would the same engine, with the same ultra fine "at the edge of the envelope" setup, make it to 800+ miles ...24 hours at Le Mans?

In 1970-something, (IIRC) Ford engineers got the DOHC 427 to push over 700hp. They detuned it to 500+/- to make 24hours.

Are you saying that if they could have found 70 weight, they could have left it peaked ..or was there another reason for the detuning?



I THINK you are thinking of the 427 SOHC...........


When I was little I always wondered what made the 427 "sock" (as it was pronounced) different from the rest. Now I can never mistake it for a DOHC thanks to that mispronunciation.


HAHHAHHAHAHA, oh man, that was great
grin2.gif


I would LOVE to have one of those engines..... Unfortunately, they fetch stupid money, similar to Chryco's 'ol 426....
frown.gif
 
Originally Posted By: buster
crazy2.gif


I don't know how it's possible to single out just viscosity as a factor for wear when so many other things matter such as engine designs etc.? Never really understood the hangup with viscosity.


Exactly. To reduce the use of lighter oils for qualifying or not so light oils over a longer duration and citing "damage" (I can be as apparently ignorant as 1sttruck
56.gif
) is so one dimensional in view ..it's null and void.


Furthermore ..under that one dimensional narrow minded and blinded view ..the national fleet should be grinding to a halt any day now. I guess ignorance of a basic principle of lubrication just manages to get "wishful thinking" vapor validity that works.

Yes, I meant SOHC ..with the umpteen feet of timing chain (I don't know the real length).
 
Originally Posted By: Gary Allan
Originally Posted By: buster
crazy2.gif


I don't know how it's possible to single out just viscosity as a factor for wear when so many other things matter such as engine designs etc.? Never really understood the hangup with viscosity.


Exactly. To reduce the use of lighter oils for qualifying or not so light oils over a longer duration and citing "damage" (I can be as apparently ignorant as 1sttruck
56.gif
) is so one dimensional in view ..it's null and void.


Furthermore ..under that one dimensional narrow minded and blinded view ..the national fleet should be grinding to a halt any day now. I guess ignorance of a basic principle of lubrication just manages to get "wishful thinking" vapor validity that works.

Yes, I meant SOHC ..with the umpteen feet of timing chain (I don't know the real length).


Six feet if I remember correctly
grin2.gif
 
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