AE Haas recommends oil pressure to decide weight

[Steve S]

Originally Posted By: fdcg27
Originally Posted By: TFB1
Originally Posted By: fdcg27
Originally Posted By: ProfPS
IIRC Dr. Haas was a chemical engineer before going to medical school.


How 'bout that.
The man has the courage to run very light oils in Italian exotics he actaully paid for.
How many of us can demonstrate that level of courage in our convictions?


But as I understand it, he mostly putters around barely gets the oil up to operating temp... If I owned one, it would have the dog do-do run out of it and not on 5W-20 oil...


I suspect that unless you actually tracked one of these cars, you'd have a hard time getting the oil very warm.
I picture myself driving one to work, and other than brief runs to redline in the appropriate gear while passing on the two lane, the car would not get run very hard.
You could only run one of these cars really hard on the street if you had diplomatic immunity.
Exactly, They are built to run and run hard.

 

[Steve S]

I have chatted by email with a couple of times, Dr Haas is an incredible guy. I don't have to agree on everything he says to not think highly of the man.

 

[Steve S]

Just because someone is an engineer [plug in what kind] doesn't mean that someone really knows more than he thinks he knows.

 

[Steve S]

Also the oil is hotter between the parts than in the sump.

 

[ProfPS]

Originally Posted By: Steve S
Just because someone is an engineer [plug in what kind] doesn't mean that someone really knows more than he thinks he knows.


Since this tread has turned to criticing a member's opinions and their own practice, please share with us your professional training and background.

 

[dparm]

I thought Haas was the one who said he drove his Maybach around in 1st gear just to listen to the engine noise? I doubt that's "easy" on the oil...

 

[expat]

Originally Posted By: dparm
I thought Haas was the one who said he drove his Maybach around in 1st gear just to listen to the engine noise? I doubt that's "easy" on the oil...


If he did so, he would not put much load on the engine! I'd say the oil would like it just fine.

 

[CBR.worm]

The only vehicle I drive regularly with an oil temp gauge is a Cayenne S. It takes a good 30 minutes of normal driving to get the oil temp up to the coolant temp. 15-20 minutes if I am towing a trailer. Oil is not a great thermal conductor.

 

[CATERHAM]

Originally Posted By: Steve S
Also the oil is hotter between the parts than in the sump.

That's why one relies on oil pressure (back pressure actually) which rises and falls based on the temperature of the oil in the bearings.

On the track oil temp's can soar if you're using WOT much of the time each lap and oil pressure can plummet under such conditions; hence the reason many performance cars spec' a 40, 50 and even a 60wt oil. On the street most high performance engines tend to run cool since it is impossible to "keep you foot in it" for very long.
Since Ali Haas' never tracks his Enzo Ferrari (I know it's a crime) and rarely if ever even exceeds 100 mph, his oil temp's never gets above 182F. That's why he has no problem running a heavy 30wt oil instead of the spec' 10W-60 and maintain more than adequate OP.

I should point out that all current Ferrari models spec' a light 5W-40 oil with a HTHS viscosity of 3.7cP. That's basically the viscosity of the oil Ali runs in his Enzo.

 

[Steve S]

Originally Posted By: CATERHAM
Originally Posted By: Steve S
Also the oil is hotter between the parts than in the sump.

That's why one relies on oil pressure (back pressure actually) which rises and falls based on the temperature of the oil in the bearings.

On the track oil temp's can soar if you're using WOT much of the time each lap and oil pressure can plummet under such conditions; hence the reason many performance cars spec' a 40, 50 and even a 60wt oil. On the street most high performance engines tend to run cool since it is impossible to "keep you foot in it" for very long.
Since Ali Haas' never tracks his Enzo Ferrari (I know it's a crime) and rarely if ever even exceeds 100 mph, his oil temp's never gets above 182F. That's why he has no problem running a heavy 30wt oil instead of the spec' 10W-60 and maintain more than adequate OP.

I should point out that all current Ferrari models spec' a light 5W-40 oil with a HTHS viscosity of 3.7cP. That's basically the viscosity of the oil Ali runs in his Enzo.
I have brought up the fact that Dr Haas doesn't push the cars. But then I wouldn't track a Ferrari If I could stomach owning one, they are just too pretty. I would use the recommended oil. Though I could drive about 60 miles to the high desert and open the car up. I did a top ender on the 2006 4 cyl Toyota 4x4 and got up to 97 mph on the speedo in 4th gear!!!

 

[CATERHAM]

An engine has no idea what grade of oil is in the sump. All it knows is what the operational viscosity is at any given moment.
The oil recommended my the manufacturer is the place to start in the oil selection process. If the spec' oil is already a 20wt or 30wt grade there is obviously little to be gained by deviating from what's recommended, but for heavier grades there may very well be a benefit in fine tune the oil viscosity to one's own application.

The bottom line is that the good doctor is correct in using oil pressure to decide the correct weight of oil to run. I would add that oil pressure correlates with HTHS viscosity, so what you're really doing is using OP to determine the optimum minimum HTHS viscosity.

 

[expat]

CATERHAM, you use 20w-50 in your Europa. Have you considered a lighter oil? Why do you think that engine requires a 20w-50 (today)


Just asking

 

[Unleashedbeast]

Originally Posted By: CATERHAM
Originally Posted By: Steve S
Also the oil is hotter between the parts than in the sump.

That's why one relies on oil pressure (back pressure actually) which rises and falls based on the temperature of the oil in the bearings.

On the track oil temp's can soar if you're using WOT much of the time each lap and oil pressure can plummet under such conditions; hence the reason many performance cars spec' a 40, 50 and even a 60wt oil. On the street most high performance engines tend to run cool since it is impossible to "keep you foot in it" for very long.
Since Ali Haas' never tracks his Enzo Ferrari (I know it's a crime) and rarely if ever even exceeds 100 mph, his oil temp's never gets above 182F. That's why he has no problem running a heavy 30wt oil instead of the spec' 10W-60 and maintain more than adequate OP.

I should point out that all current Ferrari models spec' a light 5W-40 oil with a HTHS viscosity of 3.7cP. That's basically the viscosity of the oil Ali runs in his Enzo.


Originally Posted By: CATERHAM
An engine has no idea what grade of oil is in the sump. All it knows is what the operational viscosity is at any given moment.
The oil recommended my the manufacturer is the place to start in the oil selection process. If the spec' oil is already a 20wt or 30wt grade there is obviously little to be gained by deviating from what's recommended, but for heavier grades there may very well be a benefit in fine tune the oil viscosity to one's own application.

The bottom line is that the good doctor is correct in using oil pressure to decide the correct weight of oil to run. I would add that oil pressure correlates with HTHS viscosity, so what you're really doing is using OP to determine the optimum minimum HTHS viscosity.


This is exactly what I have been doing while monitoring oil pressure in my Shelby. Ford specs a 5W-50 in the car, but from day one I was a skeptic. There was no possible way this car driven on the street would require that great of viscosity. Especially since my car had cooling mods in place that reduced engine coolant temps by ~20*F. The oil cooler by theory should also be cooler by ~20*F since it relies on engine coolant for conductive heat transfer.

I began pressure testing 10W-40 true synthetics, found it to be more pressure than required, so I dropped to a 10W-30. Oil pressures are much improved now versus the 50 grade that was recommended. Since Ford is comfortable with Motorcraft 5W-50 shearing to a heavy 30 grade, it makes even more sense.

You should see my fellow GT500 owner peers reaction when I tell them I am now currently using a 10W-30 in a car that is spec'd for 5W-50. One uneducated peer said, "Enjoy destroying your engine." HA! If he only knew more about engine lubrication dynamics and how it really worked. lol

 

[hattaresguy]

Originally Posted By: TurboTravis
Totally wrong on taking 20-30 minutes to get to 180, but some cars won't even get the oil to 180 (A newer ZO6 Vette for example). My Evo 8 that makes 800HP with 20W50 will get the oil to it's operating temp in ~10 minutes.



If I remember correctly I beleive the Enzo uses a dry sump.

Since the oil is removed from the engine in a separate tank, and I'm going to assume it has its own radiator. It very well might take that long to warm the oil up in that car. More so since I'm going to guess that it holds more like 12-16 quarts.



On the track it would warm up much faster since you could run a few slow laps at far higher loading than you would ever see on the street.

 

[Steve S]

Originally Posted By: ProfPS
Originally Posted By: Steve S
Just because someone is an engineer [plug in what kind] doesn't mean that someone really knows more than he thinks he knows.


Since this tread has turned to criticing a member's opinions and their own practice, please share with us your professional training and background.
I know enough to be able to discern if what I read is fact or opinion. How about you?

 

[CATERHAM]

Originally Posted By: expat
CATERHAM, you use 20w-50 in your Europa. Have you considered a lighter oil? Why do you think that engine requires a 20w-50 (today)
Just asking

The Lotus Twin-Cam engine is an old engine design with no valve guide seals and marginal oil pressure even when new.
20W-50 was the spec' oil back in the day. I tried M1 15W-50 once and my hot OP droppped to 33 psi at high rev's from 40 psi with the dino 20W-50. Oil consumption also doubled.

Rebuilt Twin-Cam engines with tight modern clearances often use 30wt oil.

 

[ProfPS]

Originally Posted By: Steve S
Originally Posted By: ProfPS
Originally Posted By: Steve S
Just because someone is an engineer [plug in what kind] doesn't mean that someone really knows more than he thinks he knows.


Since this tread has turned to criticing a member's opinions and their own practice, please share with us your professional training and background.
I know enough to be able to discern if what I read is fact or opinion. How about you?


Yes, I can too.

BITOG is not a fact only forum. It is the freedom of exchange of opinions and ideas that are not always fact based that attracts so many from around the world to this website that enables people to learn from one another. If personal criticism is allowed and opinions openly ridiculed, member participation and open exchange on BITOG topics will decline. This is not the first time that you have not respected others on this site. You and I have had exchanges before that were initiated by you with your inability to have an open mind or allow others to have opinions and ideas that differ from yours. Many members have left BITOG because of online behavior that has been similar to yours.

I am not going to respond any more on this off topic tangent.

 

[OVERKILL]

Agreed with those who mention that it is completely dependant upon engine, car and cooling design as to how the temperature situation plays out.

My M5 will get to operating temperature on the way to work. That is only a few Km's. 5 minutes of driving at the most. The oil temperature will be at about 70C (158F).

It takes about 10 minutes of in-town driving to get the oil up to operating temp. Which is around 95C (203F). It will stay around 90 if I'm driving on the highway (194F). And takes a lot longer to warm up than if doing in-town driving.

My engine spec's an oil with an HTHS minimum of 3.5. Originally the engine was spec'd for 10w60, however that was dropped for cars produced after 03/00, which can use BMW 5w30 (3.5 HTHS IIRC). HTHS is the important thing, not the API grade on the oil container.

 

[expat]

Originally Posted By: CATERHAM
Originally Posted By: expat
CATERHAM, you use 20w-50 in your Europa. Have you considered a lighter oil? Why do you think that engine requires a 20w-50 (today)
Just asking

The Lotus Twin-Cam engine is an old engine design with no valve guide seals and marginal oil pressure even when new.
20W-50 was the spec' oil back in the day. I tried M1 15W-50 once and my hot OP droppped to 33 psi at high rev's from 40 psi with the dino 20W-50. Oil consumption also doubled.

Rebuilt Twin-Cam engines with tight modern clearances often use 30wt oil.


Fare enough.
I only ask as my Triumph, when rebuilt was given 10w-30 and seems happy with 15w-40 OP 20psi @750 rpm hot.
My gut feeling is to err on the heavy oil side.
The car get summer use only.
Now, IF oil film strength was so low as to allow metal to metal contact at bearings or Cam (I have solid lifters), would I see it on the oil pressure gauge? IF I have 10 psi per thousand rpm can I be sure that, at some point, I don't have metal to metal contact?

 

[expat]

It may also be worth noting that the area of an engine where the oil is subjected to the highest temperatures, the piston, ring and ring cyl interface are not pressure fed.
I can imagine a situation where the oil in this area may easily be overstressed, but this would not be indicated by an OP reading or oil temp reading (taken at the oil pan).