Introduction:

[Winston]

This is very interesting info regarding oil viscosity. Especially from someone that has seen many failures that can be attributed to oil viscosity.

Also, this is different than AEHass' writings since Hass writes from a technical/theoretical perspective while Robert writes from a real world (OK a portion of the real world) perspective.

However, most of our cars do not see these extreme conditions (high heat and/or heavy load). So, it would not necessarily apply. He is also talking about bearing failures in particular. He is not talking about cylinder wall wear, cam lobe wear, etc.

Also, I wonder if the need for high viscosity is related to the high torque/low rpm nature of these V8 engines.

[ August 25, 2005, 06:43 PM: Message edited by: Winston ]

 

[Robert Herndon]

Winston: We live in an extreme climate. The information I share isn't intended to work in a colder region.

If 5/20 is 'doing it' for you where you live, I wouldn't stop using it.

I keep on using 20/50 in my (old) 125,000 mile Crown Vic and it is still working. The patrol guys are really hard on cars and we give the old cars to the newest guys.

As Patrol Sergeant in charge of vehicles, I can have anything I want put in our fleet. I am using my 'testing' to arrive at a standardized oil fleet-wide.

At this time, I am considering a 15w40, probably Delo 400 or Shell Rotella T for the fleet. I can buy it in bulk at Costco at a very good price, which saves the department money and keeps the Chief happy.

I think it strikes a good balance between the 5/20 and the 20/50 oils. It has served me well in my Turbocharged Mercedes-Benz Diesel. Oil pressure is very consistent and cleanliness is excellent.

A few years ago, our former Chief tried Mobil 1 10/30 with 5000 mile filter changes and the oil and filter changed every 25,000 miles.

The results were horrific.

I have never seen so much sludge in an engine and I verified the function of the PCV personally.

We still have 3 cases of 10/30 Mobil 1 in storage.

By the way, I still hold several valid ASE Master Ratings, with past BMW ACT and MBZ Certified Technician Ratings. I held a valid Smog License in California until 2003.

I still work on a part-time basis for a local BMW Dealer where I install a lot of the Dinan Performance Products.

I also rebuild carburetors for several local shops from time to time. The nice part about having this relationship is, I have access to a Flowbench, Chassis Dynometer, Bead Blaster, Hot Tank, Wheel Balancers and all the literature and test equipment I can lay my hands on, including BMW's GT-1 Test Database.

I also do a number of 4-Speed Muncie buildups and Differential work for the local circle track community during race season.

Just to let you know I still wrench enough to keep my skills sharp.

I'm not the smartest person in the world, but I try to use those things that really work. I also try to look at things from a practical standpoint.

My Pontiac is basically a de-tuned race car, so what I use on it really can't be viewed as any kind of example.

However...in the case of my daily-driven 1978 Mercedes-Benz 300 SD, that is a different story.

I built that engine with a number of performance modifications and the car is driven 108 miles a day to and from my work. I have used Shell Rotella T 15w40 in all my diesels and I think it is very good in that capacity.

My Dad and I just finished a new GM 6.2 Litre Diesel V8 for his 1972 Chevrolet Truck. We are breaking it in on Chevron Delo 400 15w40 as he can get that brand a little cheaper.

I honestly don't think there is a better diesel engine oil on the market than Rotella or Delo. I think it works well in gasoline engines too.

I must admit, I love the discussion and sharing of information in this forum...Robert

 

[427Z06]

quote:

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Originally posted by Robert Herndon:
Farrar: Trouble CHP was having was the oil light coming on after high speed runs in +100°F conditions. We have seen the same thing with less than 40,000 miles on the cars.

With the 5/20, the oil pressure would drop low enough at idle that the oil light would 'flicker' on and off until the engines cooled down.

---

Sounds like a air-flow/cooling problem to me. We have large Ford trucks pulling boats around here in similar summer weather with nary a problem. Do your CVPIs have engine oil coolers? Any oil temperature data?

 

[MGBV8]

Winston

Buster posted some interesting comments added below. Perhaps a short term gain!

IMO AEHaas is balancing cooling of thin against wear protection of thick. For high performance road use and increasing to track the balancing act may be more complex. RL provide high ester, high Zinc, high HTHS compared to most other oils.

The ester element allows thin without perhaps the wear issue, ignoring the cost issue, and just looking at oil, RL appears to be the oil to be the baseline?


Thinner motor oils such as 5W-20 or even 0W-20 are becoming more popular these days and are even specified by some OEM's (FORD & HONDA) on new 2001 cars.
Although these oils are promoted as "energy conserving" they generally trade a gain of less than 0.1 MPG in Corporate Average Fuel Economy (CAFE) for shorter useful engine life.
FORD which has previously designed cars to have 10 year or 150,000 miles life has reduced the mileage life expectation to "beyond 100,000 miles" on vehicles that are operated on SAE 5W-20 Motor Oil.
HONDA only claims "useful life" as 7-years or 70,000 miles in EPA certifications for their CIVIC which uses SAE 5W-20 Motor Oil, while the previous model that utilized SAE 5w30 Motor Oil was certified for 10 year or 100,000 mile durability.
Since both HONDA and FORD Warranty their NEW cars for ONLY 3-years or 36,000-miles the reduction in engine life expectancy is not a factor.
By contrast Mercedes-Benz recommends use of ONLY Synthetic Motor Oil that is at least SAE 5W-40! This is a recent increase in recommended viscosity from SAE 5w30. Apparently customer research indicated that engine longevity is more important to typical MB customer than fuel economy.

 

[Robert Herndon]

427Z06: No temp data...sorry. Airflow is a huge problem because of the Bees and Butterflies. We are constantly having to clean the cooling fins of the radiators and condensors.

Bottom line is, these guys are really hard on these cars. I think we expose them to conditions far beyond what any other human being would do. With the heat, airflow, rpm and load issues, the heavier oils do what we need them to do.

I agree with MGBGTV8's post and MBZ's requirement for a higher quality oil, especially when you consider the cars quite often go to the Arab market...Robert

 

[427Z06]

quote:

---

Originally posted by MGBV8:
Thinner motor oils such as 5W-20 or even 0W-20 are becoming more popular these days and are even specified by some OEM's (FORD & HONDA) on new 2001 cars.
Although these oils are promoted as "energy conserving" they generally trade a gain of less than 0.1 MPG in Corporate Average Fuel Economy (CAFE) for shorter useful engine life.
FORD which has previously designed cars to have 10 year or 150,000 miles life has reduced the mileage life expectation to "beyond 100,000 miles" on vehicles that are operated on SAE 5W-20 Motor Oil.
HONDA only claims "useful life" as 7-years or 70,000 miles in EPA certifications for their CIVIC which uses SAE 5W-20 Motor Oil, while the previous model that utilized SAE 5w30 Motor Oil was certified for 10 year or 100,000 mile durability.
Since both HONDA and FORD Warranty their NEW cars for ONLY 3-years or 36,000-miles the reduction in engine life expectancy is not a factor.
By contrast Mercedes-Benz recommends use of ONLY Synthetic Motor Oil that is at least SAE 5W-40! This is a recent increase in recommended viscosity from SAE 5w30. Apparently customer research indicated that engine longevity is more important to typical MB customer than fuel economy.

---

Isn't that a quote from that "SynLube™ Lube-4-Life™" website where they want you to buy their super expensive oils and never change it? I don't know how much credibility I'd be willing to give them. They kinda' remind me of those "ProLong" commercials.

 

[427Z06]

quote:

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Originally posted by Robert Herndon:
Bottom line is, these guys are really hard on these cars. I think we expose them to conditions far beyond what any other human being would do. With the heat, airflow, rpm and load issues, the heavier oils do what we need them to do.

---

Yep...a thick oil band-aid is the easiest and least expensive way to hide the problem. Visions of M1 spec'ed for the C4-C5 when GM management didn't want the expense of oil coolers.

 

[Geoff]

quote:

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Originally posted by Robert Herndon:

The large (3.00") journal diameters necessitate a lot of oil pressure and volume...

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This is an interesting point. Wider journal diameters can significantly increase the bearing speeds. Viscosity is probably a player here.

I am waiting for a report on my '04 Land Rover v-8 with Castrol Syntec Blend 20w-50 and will post soon. Although I'm have trouble believing the sincerity of car manufacturers on 20 weights, 50 grade is thicker than I have used since my '78 Rabbit (sold at 160K miles and never used oil). However, this is the oil the dealer uses.

 

[vicmackey]

Funny thing is I was a patrol officer for 5 years before I left the profession for greener pastures and we never had a problem using 5w30, 10w30, or 10w-40 in our fleet of 4.6l cars.

Your climate is really no different than mine and we never had any problems.


BTW, I called the fleet manager at a local PD who is a friend of mine and he said he has never heard of any such problems that you are talking about and he is in contact with fleet managers from all over the country on a regular basis.

Did you say you were a patrol sergent AND in charge of all the vehicles? You must work at a really small department if you can do both jobs. And a part time wrench to boot? How on earth between all these gigs do you have time to do your oil "testing"? I work 40 hrs. a week and have a hard time setting aside 30 min. to mow my yard.

I also have one other thing that I just got to ask. Do you really think it is logical to pick a oil for a fleet of cars without one single oil analysis?

I think your testing is a little flawed my friend.

 

[farrarfan1]

quote:

---

Originally posted by Big O Dave:
Hey farrar! It's a LOT hotter in Fresno than it is in your neck of the woods... with your cold winters, you NEED 5w30, but in the Central Valley of California, it's HOT in the summer and never really all that cold in the winter.

Could this account for your differing experiences?

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I work in the very southern part of the state at the Kentucky state line near Louisville. It gets plenty hot in the summer and our winters are generally pretty mild.I think too much emphasis is put on ambient temps effect on oil. The CVPI's have an oil to water type oil cooler mounted behind the radiator. 95 degrees in Indiana is the same as 95 degrees in California or Florida or wherever.Our cars are assigned to us individually so they only are run about 8 hours daily but we can use them off duty so they get a lot of typical "city" stop and go driving. I can only use my department and the local departments I work with as references but I just don't see that many problems with the motors lasting. Now the transmissions are a different story...

 

[TonyMazz]

Beebe / Mulligan ....Can't remember as I was about 9 then, but John dove into the 6's before his crash didn't he ?

 

[XS650]

quote:

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Originally posted by Robert Herndon:
427Z06: No temp data...sorry. Airflow is a huge problem because of the Bees and Butterflies. We are constantly having to clean the cooling fins off the radiators and condensors.

---

Have you considered screens for the radiators and condensors? I don't like them because the screens theirselves are restrictive, but they are lot easier to clean so the average restriction over the life of the car should be lower.

 

[rpsvo]

quote:

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Originally posted by vicmackey:
...
I think your testing is a little flawed my friend.

---

Well let's not kick a gift horse in the mouth. I've learned the hard way, even with my ongoing mechanical engineering education, that I can always learn more as long as the "model" is appropriate.
To claim that his testing is flawed is a flawed statement in itself. This is not a laboratory quality conditions test by any real measure. Mr. Herndon never claimed this, however he did inform us of his real world experience which needs to be understood instead of criticized. For example, did we take into acct the humidity differences btwn KY & SoCal? His cars see a lot more dust. If a mortician buries more alcoholics than any other reason for death, does he need blood samples to be sure?
Let's ask better questions and learn instead of attacking credibility. Do you work for Carl Rove?

Robert, did you come across genuine improvements by other people playing w/ very high oil pressures and their results? As I understand it, Jack Roush (in the 1970's - 80's) ran pressures above 80psi for some of his race engines (Clevelands) to compensate for deficiencies above 6k rpm. Any insght?

 

[nickmckinney]

quote:

---

Robert, did you come across genuine improvements by other people playing w/ very high oil pressures and their results? As I understand it, Jack Roush (in the 1970's - 80's) ran pressures above 80psi for some of his race engines (Clevelands) to compensate for deficiencies above 6k rpm. Any insght? [/QB]

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General rule of thumb is 10psi for every 1K of RPM. I think they were spinning those to 8~9K at the time. The Cleveland oiling system was about the worst to come out of Detroit during that era.

I can see the problems Robert is having with those 4.6 Ford mods, I heard about it elsewhere that CHP was using 15W40 also. The real problem though is the drainback from the heads. A long term high RPM run theres just little oil left in the pan, its all in the heads especially the passenger side head.

There are people running 0W10 at near 10,000rpm in the mod motor just to keep the valve adjusters from pumping up hard, so it can be done. But without an option of a larger oil pan and an external drainback for the passenger head, I can see using 15W40 especially in a 4.6 engine that is rarely cold started.

 

[XS650]

quote:

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Originally posted by farrarfan1:
95 degrees in Indiana is the same as 95 degrees in California

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That's hard to argue with, but it's not the same as 105F to 110F in a place that routinely sees 100F+ temperatures a good share of the summer.

When it gets down to 95F in Fresno people start getting their winter clothing out

 

[vicmackey]

I'm sorry but his "testing" is flawed.

How is his testing accurate at all when he is not doing analysis?

I guess he can smell, feel, see, or taste the differences.

 

[T-Keith]

quote:

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Originally posted by XS650:


When it gets down to 95F in Fresno people start getting their winter clothing out

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When it gets to 95F in Minnesota, people die.(not a joke)

-T

 

[XS650]

quote:

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Originally posted by T-Keith:

quote:

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Originally posted by XS650:


When it gets down to 95F in Fresno people start getting their winter clothing out

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When it gets to 95F in Minnesota, people die.(not a joke)

-T

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I was on a plane leaving Minneapolis one winter in lovely -25F weather.

As the plane was rolling back, the pilot announced that the temperature in San Francisco was 40 degrees (pause) above zero.

(Followed by applause and cheers from the passengers)

 

[427Z06]

quote:

---

Originally posted by nickmckinney:
I can see the problems Robert is having with those 4.6 Ford mods, I heard about it elsewhere that CHP was using 15W40 also. The real problem though is the drainback from the heads. A long term high RPM run theres just little oil left in the pan, its all in the heads especially the passenger side head.

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This is an example of a "distribution problem", not that the oil was too thin for the bearings. Running the thicker oil will engage the bypass sooner and limit total flow at high RPMs, masking the real problem.

 

[427Z06]

quote:

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Originally posted by Robert Herndon:
I took a 1962 Forged 421 Crankshaft, machined the mains down from 3.250" to 3.00" and used a custom made, teflon coated skirt piston...Robert

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Is your crankshaft cross-drilled?