More on Thin Oils, A Used Oil Analysis

Once you get enough laps under your belt, you can be waving to the corner worker, carrying on a conversation with your DI, correcting a lurid slide all at the same time. There are plenty of 1-5 second moments on every lap to look at the gauges--the safest place is on the longest straight. But, I do watch these gauges more or less all the time. On the street I look at each gauge at least twice a minute.

Then there is the long term brain function of reading the gauge (lets say) once a lap on the main striaght where less is happening. You train your brain to watch the temp rise--lap by lap, at some point it will stabilize, and then if it moves you dedicate brain power to why. If it stays where it stabilizes, it is but a mere glance of brain activity with almost no thought involved. Look, if same-as-before then ignore else leave driving zone (i.e. slow donw) and think about it.

 

Maybe, he's clearly very knowledgeable...the problem is that he's not applying the knowledge properly to automotive oil system design and completely misrepresenting the risks and benefits.

 

But I'm not arguing that it is safe to put thin oil in a car used on a race track. I am arguing that it is safe if you know how to read the oil data sheets AND compute the temperatuer at which to stop driving if you are on a race track (or whereever). Even now, I tell people who are in a situation where they will not stop or slow down if the oil temp gets above 305dF to use 20W-50 oil in the engine. Why--because 20W-50 has an HTHS at 330dF that the specified 10W-40 oil has at 305dF. Likewise, if you are someone who CAN watch the oil temp gauge and will slow down or stop if the oil temp gets above 285dF, THEN and only then can you get away with 10W-30 oil at the race track--AND ONLY if you go do the background research to know how the oil is supposed to perform. You CANNOT simply pick a random 10W-30 oil, dump it in and expect to get away with it.

{BTW, the only 10W-30 oil I know of that meets the HTHS numbers we have been talking about is Redline 10W-30. The RL 5W-30 oil is close but no cigar. Their 0W-30 oil is dangerous on a race track in our cars.}

 

One other point. I would not buy a car that had not been run with manufacturer's reccomended oil. Period.

I would also not buy a car that had been short tripped.

 

Mitch,
I have a tremendous amount of respect for you and your opinions and your position in this argument is no different. In every post I read of yours on this subject the disclaimers/limits are always made clear.

That said I have 2 concerns with your argument and method. First is that I don’t believe that are enough known in the system to do the math. When you go to the table and look at the viscosity of the factory oil at 305F you come with a number…..but the factory only gave you that number as a reference. The oil in the bearings is certainly hotter than that when the gauge temp is 305 so you really don’t know what the critical viscosity is or what the upper temperature is. Just matching the number at 305 might be ok if the temp vs viscosities were linear but it never is on the graphs I’ve seen. This all means that you don’t actually have any idea how a thinner oil at a lower temp compares because you don’t actually know any of the points you are trying to match.

The second issue that I pointed out already is that the 305 temperature was not chosen randomly. It was chosen to be above any temp the oil is likely to see in a single failure condition, like dropping a water pump belt, obstructed radiator, ect. Oil that is good to 285 does not achieve this making complete engine failure a very real possibility during any overheat condition.

It just seems like a very bad idea to me. You get gain so little hp that you most likely can’t measure it and in return you give up every bit of safety margin that the factory built into the system. Finding an oil that reduces wear but still matches the factory specs is a great idea, but if the oil does not meet the temp specs then the oil does not meet factory specs and is an inferior option.

 

I was thinking the same thing...that would be a tough one to explain on the PPI

 

Jim, Mark- Do you mean you would not buy a car that did not use the Shell oil or one that did not use the correct weight oil? Much better oils available than the Shell Ultra Helix in the correct weights.

Taz
Terry Phillips

 

I personally would be looking for the correct weight and paying more attention to the high number than the low one, that synthetic was used if specified, and the intervals don't exceed spec. Seeing 10w30 when the manual says 10w50 will set off every alarm there is and why would I listen to the story instead of simply moving on to a car without stories…unless the price was very right.

It’s like most any modification really, it can generally only hurt the value but if it’s what you want it’s your money….god knows I’ve never learned to leave things stock.

 

Correct weight. That said we've used Shell Ultra Helix in P 4/5 with very good results.

It held up well in Bahrain on the F1 Course for hours of hard running on a VERY hot day. At the end of the day the oil temps wouldn't come down so we backed off a little but I suspect that was all the sand the oil coolers ingested. After a massive cleaning she runs very cool again.

On a side note and I realize that many don't like Evans Coolant, we also run that and it really seems to work for us dropping coolant temperature about 10 degrees F. You do have to watch your coolant gauge as Evans runs at 0 PSI and doesn't boil until 400 F.

Evans will flash so we have a full on board fire system.

 

I am under the impression that Dr. Ali Haas is an MD and a surgeon. I don't think he is a formally trained tribologist. Maybe he will tell us.

Although I do not buy into his extreme devotion to thin oils, I am grateful to him for having begun my oil education and turned me on to BITOG ("Bob is the Oil Guy") where my education continues.

 

This is correct. Dr. Haas has never claimed he was a tribologist. He has stated various times on F-chat and BITOG that he is indeed a surgeon.

 

Yikes.

 

Mark, Jim- Thanks. On P4/5, I do not imagine there are too many other synthetic oils available in 10W-60, so understand your choice of Shell UH.

Naturally as soon as I typed that, I had to look. Castrol and a whole bunch of off-names make 10W-60 synthetics, it turns out. The Shell looks as good or better than any I saw.

Taz
Terry Phillips

 

Being a tribologist, I love to watch oil threads go sideways! Here's what I can tell you.
Just because an oil is less viscious, doesn't mean it's of lower quality. The additive package has more to do with the quality, than the base oil's VI.
Now, to the OP~
Your copper and antimony seems high for so few miles. If your sample were for 15,000 miles, then I could see the antimony levels up, but your copper is still too high...even for 15,000 miles with no make up oil added. This is something to keep an eye on. This is the value of oil analysis. That, and developing and oil change interval.

 

The argument here isn’t about thinner oils being lower quality; it’s about them being an appropriate choice for the application. The bearings require some minimum viscosity to prevent metal to metal contact and the factory recommended viscosity has been tested and shown effective, lower viscosity oils have not. I have to believe that if there was free hp and reduced wear rates available by a simple viscosity switch and nothing else was compromised the engineers at the factory are plenty smart enough to switch the oil and take the free stuff…..engineers just love free stuff.

 

P 4/5 needs 0-60.

Best

 

On this issue I kind of have to laugh at myself a bit because seeing 10w60 was used instead of 0w60 wouldn’t really trigger any alarms with me…..but I know it should.

Having destroyed more than my fair share of engines over the years I am very sensitive to things that will make an engine go bang but since I’ve never actually worn an engine out on the street the wear rate stuff just doesn’t register with me.

 

Mark,

Interesting discussion. I personally agree with your point about sticking with recommended oil weights. It seems to me that the vehicle manufacturer has spent at least some time considering the lubrication requirements of its car in order to avoid engine damage. They are not just picking numbers out of thin air.

Now, along those lines, I was looking at the manuals for the 328 the other day, and noticed that in the Technical Specifications, Ferrari originally recommended Agip SINC2000 10W50. In a later service bulletin, they noted that Agip no longer manufactured as 10W50, and changed their recommendation to Agip 10W40. So, although Agip does not offer a 10W50, other companies do. Should we be using a 10W50 in the 328, or are we good with 10W40 as an alternative? I know that the difference in viscosity that Dr. H is talking about is much more dramatic, going with an extremely thin oil (0W20?). But is there any significant difference here to be concerned about between the 10W40 and 10W50? Seems to me they are close enough functionally that it should not make a difference in normal street use or even "spirited" driving.

Thanks.

 

That is where it gets tough isn’t it….
The easy way to answer the question is to say just buy a 10w50 synthetic and don’t give it another thought. When you go to sell it you have records that say 10w50 just like the owner’s manual says and no explaining to do. That’s what I do both because I’m lazy and because I know how I am with engines. If I was at the store and needed oil I would buy a 10w60 or 20w50 before I bought a 10w40 and again not give it another thought. I can tell you with certainty that this approach does work in a 308 engine designed to make 240hp but actually making 600 (nearly) hp no matter how much abuse you hand it. The wear rates may well be higher than they could be but you aren’t ever going to break an engine by using a thicker oil (unless it’s really cold out).
The right way to answer the question is to do what Dr. Haas and Mitch have done and pull the temp vs viscosity graphs for the original oil, the factory recommended replacement and anything of the option you are looking at. I would be a little, ok a LOT more conservative though and be looking for the replacement oil to be providing equal or higher viscosity at all temps from say 200F to 350F so I know without question that I haven’t decreased the load handling capacity of the main and rod bearings. When you do this you will most likely be selecting a 10w50 synthetic but at least you’ll know without question you’ve made the safest choice.

 

Jim- My mistake. Since the OM specifies 10w-60 for the Enzo, I assumed that was what you were using. I found a flyer on the Helix Ultra 10W-60, but was unable to find anything on the 0W-60. I did find the Castrol 0W-60.

Interesting blurb on the 10W-60 racing oil being developed for the 360 Challenge cars and suitable for BMW M cars.

Taz
Terry Phillips
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More indication that going thinner is these engines is the wrong direction. Manufactures don't bring products like this to market if there is no market for them. For as long as I can remember (I worked in an auto parts store in HS in the early 80s) 50 or 60 weight was the oil of choice for racing....because bearings fail when you try to use anything thinner.

Oils have gotten a lot better over the years but nobody who cares about speed goes to thinner oil, they rev the engine higher and go faster

 

Mark- I have a bad habit of bouncing my engine off the rev limiter (fuel cut-off) occasionally, so you know which way I am voting.

Taz
Terry Phillips

 

{I want to thank MK E for agreeing that I always put in generous amounts of caveats.}

There are troubling issues with thick oils, also. Do you know what happens to a thick oil at startup (while its cold) and any dose of throttle is applied?

In the main bearings, there is this phenomonom called Hydrodynamic Pressure. This is the phenomonom that enables the main and rod bearings to survive under normal use. As the conrod turns on the crankshaft the combination of surface velocity on the bearing, pressure from the cylinder, and the flow of oil across the bearing create a fuild situation where vast forces can be sustained--approximately 100X+ that which could be supported by the oil film itself (without the movement). {The journal bearing is not supported by the oil pressure of the oiling system, it is supported by this hydrodynamic wedge.}

Now, in a cold engine with cold oil, there are situations where any large amount of pressure in the cylinder (like from a stab at the throttle) can create a situation down at the bearing where enough pressure is applied that the thick and stiff oil becomes more viscous than the babbit bearings themselves. Instead of shearing on the oil surface, the rolling con rod has to slide somewhere, and that somewhere is generally the soft babbit. This is one way to spin a bearing. The thicker the oil the more gently one needs to be until the oil comes up to temperature. So, if you want to get in a drive, use a thinner oil (subject to the caveats below).

There are also troubling issues with thicker than designed for oils in the ring package (and cylinder walls). Research has shown that the rings and cylinder walls are better lubricated (and cleaned) wth thin oils than with thick oils. This is a sliding friction lubrication problem. Now, most of the time, the oil used is not so out of specification that this becomes an issue, however, the rings may get gummed up if the oil never gets hot enough to thin out and allow the cleaninig actions to occur. Thus cars used in short duty should use thinner oils.

Thirdly, there are issues with SM oils. In SM oils (the stuff you mostly find on the shelves thesedays) the oils have greately decreased the amount of ZDDP (the primary anti-wear agent since the early 1950s) from 1200-1900 PPM to under 800 PPM (starburst) in an attempt to make Catalytic converters survive more than 120K miles. In American engines the valve train has been rollerized--the cam tappet rolls on a bearing onver the camshaft, the valve is actuated by similar bearing means. In our high performance engines the cam directly impacts the tapet which directly impacts the valve. This kind of friction (and need for lubrication) is very much like that of a old flat tappet american V8 from the 50's through 70's. These kinds of engines are having severe issues with SM oils. Simply running one grade heavier oils is not sufficient to make up for the lack of this antiwear additive. For our kinds of engines, I do not buy anything with less than 1100 PPM of Zinc or Phosporous (the major atoms from the ZDDP molecule). So, for example, Mobil 1 (with no added sufixes) has an anemic 800 PPM of zinc, while Mobil 1 T&SUV has plenty of zinc. Unfortunately, if you what to garner this information, you have to look it up on the web.

Finally, this whole discussion should have driven home the fact that oil is a lot more complicated than xxW-yy number scheme concocted up by SAE in the 1930s.

For a garage queen, the most important number in the oil data sheet is the TBN--total base number--this number tells how well the oil will reduce acid products of combuston during long stays in the garage.

For a car driven a lot of miles but never sees high oil temps (>230dF) but with seldom oil changes, the important numbers are the TBN (above) and the amount detergents and dispersants.

For cars driven in heavy street use but not on race tracks, the important numbers are -xx (operating viscosity) and HTHS.

For cars driven on race tracks where the oil is changed monthly or more often, TBN, detergents and dispersants are almost unnecesary--race oils drop these to low levels to allow the oil base itself to occuply more of the fluid.

When we get to high oil temps, the important number is HTHS, and important property of HTHS is that a triffling more than necessary cuts wear by massive amounts. So, for example, only; say we have an engine that just begins to see accelerated wear at HTHS=4.0cP. By 4.1cP wear is down by 3X-4X and by 4.2cP is is essentially gone. This actually agrees with MK E's basic tenent not to use an oil under spec--even by a little. It also agrees with my tenent--know where your oil goes out of spec by looking at the oil temp gauge.

If you want to experiment with oil grades on your car--learn about oils and what the number mean, then add in what you car does with its current oil(s) keeping a log of use versus peak temperatures. Only then is the operator at a point when deviation from factory recommendations is reasonable without fear of catastrophy. If you don't want to learn about oils, how they work, and how temperature effects them, stick with factory recommended oils--which as we saw above has gotten almost impossible to do without learning about oils, additives, and numbers. Catch 22.

Summarizing this thread

A: use as little throttle as possible until the oil temp gets to 100dF
B: use as few revs as possible until the oil temp gets to 140dF
C: find oils with HTHS numbers above 4.2 (manufactures data sheet is only option--its not printed on the can)
D: find oils with Zinc of Phosporous numbers above 1100 PPM (also, not printed on the can)
E: race oils are changed often (monthly) and are for cars on race tracks
F: garage queen oils need a stiff TBN
G: one gains (or looses) about 30dF for every increment in oil weight change (-yy) -40 to -50; for example
H: one gains cold start performance by decreasing the xxW number at the expense of HTHS numbers. You canot have both.

 

Taz

That's the one although I think I have some marked at 0-60. It's been replaced by Quaker State "Q" which is the same stuff.

HTHS # seems good for my use.

 

I know this was mostly a "thick versus thin" thread, but I have a question - this also is a long running topic on corvette boards for some reason. Maybe because most of them are without oil coolers.

Anyway, a large following uses Red Line. Much is made of the fact that it is "ester-based".

OK - but so what? IIRC (<>correctly) in chemistry an ester is a very broad category of compounds which is basically a substitution of some organic molecule onto an acid molecule in place of a hydrogen. Surely these makers are not just mixing some kind of acid into some hydrocarbon chain oils and reacting them???

One would think that to make this work as the base oil of a formulation, you would have to be quite purposefully specific about just what kind of ester you were using...Does any manufacturer specify, or just keep it proprietary? In other words, what really is the advantage over a mostly linear hydrocarbon base in a certain weight range?