Motor oil weight for a tracked Coyote?

[UnleashedBeast]

A UOA will only reveal the base oil used if oxidation is tested. Not all labs perform that test. OAI does, a.k.a. Polaris Labs.

5W-20 engine survivals in the past 10+ years is more reason to understand that thicker isn't better. On BITOG forums, I learned a phrase that meant a lot.

"Thin as possible, thick as necessary."

A doctor tested oil pressure in his Ferrari, all the way down to daily driving with 5W-20. His car is recommended for 5W-40 on the street, and 10W-60 on the track. Oil pressure testing proved that daily driving duties required nothing more than a robust 5W-20.

Dr. Haas - Ferrari chat

Motor oil 108 is a great section.

"One of the members of the Ferrari Chat web site went from a 40 to a 30 grade oil in his Ferrari 355 for racing in Texas. He noticed a drop in temperature but no change in oil pressure. This may seem odd but really makes perfect sense. Since the 30 grade oil is thinner he got better flow and therefore better cooling. The oil was at a lower temperature so it was not as thin than it would have been at the previous higher temperature. Cooler engines last longer. Fact: The higher the temperature, the greater the wear, all other things being equal."

"If you are using XW-50, go to a 0W-40. If your pressures are still too high go to a 0W-30 and so on."

"When I took delivery of my 575 Maranello I drove for 500 miles then changed the oil to 0W-30 Mobil 1. There were no changes in operating pressure or temperature. Starting the engine seemed faster though. I called up FNA and was told that all new Ferrari Maranellos are delivered with 5W-30 Shell Helix Ultra. That is when I decided to try the 0W-20 Mobil 1. I could have gone to a 10 grade oil as my pressures were still excessive while driving around town. I do not drive on the track."

 

[kcbrown]

A UOA will only reveal the base oil used if oxidation is tested. Not all labs perform that test. OAI does, a.k.a. Polaris Labs.

5W-20 engine survivals in the past 10+ years is more reason to understand that thicker isn't better. On BITOG forums, I learned a phrase that meant a lot.

"Thin as possible, thick as necessary."

But if thicker isn't better, then why so much concern about shearing?

Honestly, while your knowledge about oils is impressive, your judgment about oils appears (to me, at any rate) somewhat questionable. You emphasize differences that appear to make no real world difference to speak of. That's certainly your prerogative (everyone's entitled to their opinions), of course, and I think it's useful in the end to understand the differences in question. But it's one thing to understand the differences, and quite another to understand their real-world effect.

I do find this a fascinating subject, as you can hopefully tell, so I do not at all feel this thread is a waste of effort in any way, and you should not take any of this as a slight against you, nor should it discourage you from sharing your quite considerable knowledge of oils. But I do believe it is a disservice to fail to make clear that the differences in these oils are almost certain to have no significant (if any) real-world effect, i.e. effect on the end result.

When the real-world difference between "sufficient" and "best" is as minimal as it appears here, what exactly is the point of distinguishing the two, other than perhaps as an academic exercise?


None of the above should discourage you or anyone else from the academic pursuits involved in any of this. The discovery of substantially elevated lead wear levels in GT500 engines due to oil that maintains a 50 weight viscosity (a discovery that, from what I can tell, should be attributed to your efforts -- kudos!) should illustrate the immense value of these academic pursuits. I'm just concerned about inordinately magnifying the differences we see in these oils, particularly when that GT500 experience shows that some differences really do matter in the real world. I don't want the signal to get lost in the noise.

 

[JAJ]

...I want whats best fo the engines longevity, cooling and performance...

Motul 300V 10w-40. Good cooling, perfect viscosity and HTHSV.

Pricey though. I used it in some of my BMW's.

 

[Mountain]

A UOA will only reveal the base oil used if oxidation is tested. Not all labs perform that test. OAI does, a.k.a. Polaris Labs.

5W-20 engine survivals in the past 10+ years is more reason to understand that thicker isn't better. On BITOG forums, I learned a phrase that meant a lot.

"Thin as possible, thick as necessary."

A doctor tested oil pressure in his Ferrari, all the way down to daily driving with 5W-20. His car is recommended for 5W-40 on the street, and 10W-60 on the track. Oil pressure testing proved that daily driving duties required nothing more than a robust 5W-20.

Dr. Haas - Ferrari chat

Motor oil 108 is a great section.

"One of the members of the Ferrari Chat web site went from a 40 to a 30 grade oil in his Ferrari 355 for racing in Texas. He noticed a drop in temperature but no change in oil pressure. This may seem odd but really makes perfect sense. Since the 30 grade oil is thinner he got better flow and therefore better cooling. The oil was at a lower temperature so it was not as thin than it would have been at the previous higher temperature. Cooler engines last longer. Fact: The higher the temperature, the greater the wear, all other things being equal."

"If you are using XW-50, go to a 0W-40. If your pressures are still too high go to a 0W-30 and so on."

"When I took delivery of my 575 Maranello I drove for 500 miles then changed the oil to 0W-30 Mobil 1. There were no changes in operating pressure or temperature. Starting the engine seemed faster though. I called up FNA and was told that all new Ferrari Maranellos are delivered with 5W-30 Shell Helix Ultra. That is when I decided to try the 0W-20 Mobil 1. I could have gone to a 10 grade oil as my pressures were still excessive while driving around town. I do not drive on the track."

...but, let's not astray from the fact that one cannot simply look at oil pressure and engine temperature and/or oil temperature. If you are going to go so far as to look into things this deep, one would need to run an oil anaylsis, in conjunction, to further help quantify how well the change in oil viscosity is working inside you engine... What I mean is that you can monitor pressure and temperautre, but that isn't going to tell you that you are holding a proper hydro-dynamic film to protect material surfaces from each other.

 

[Pentalab]

...but, let's not astray from the fact that one cannot simply look at oil pressure and engine temperature and/or oil temperature. If you are going to go so far as to look into things this deep, one would need to run an oil analysis, in conjunction, to further help quantify how well the change in oil viscosity is working inside you engine... What I mean is that you can monitor pressure and temperature, but that isn't going to tell you that you are holding a proper hydro-dynamic film to protect material surfaces from each other.

Points well taken. If the oil is too hot, the real ticket might be an oil cooler, vs a higher viscosity oil....or perhaps an oil cooler + a slightly higher viscosity oil. I mentioned this b4, Both K Belle + FRPP whipple include 160 deg F, T stats with their blower kits.... to replace the oem 180 F unit... ( which is fully open by 195F). You could conceivably lower both oil temps and CHT's by using a 170 or 160 F eng rad T stat.

If one used a real oil cooler, with its own T-stat, then you could regulate oil temps even better. (separate oil cooler rad)

Will an UOA even tell you that you are holding a proper hydro-dynamic film to protect material surfaces from each other ? It would be interesting to see a UOA done after each oil change..and always using the same brand /viscosity of oil. And also send samples off to several labs. Then try and correlate the entire mess.

I'm going to try some more of this RP HPS 5W-30 next month....along with another FRPP filter. I see they also make it in 5W-20, 5W-30, 10W-30,10W-40, and 20W-50.

Between the increased ZDDP levels, 'synerlec' and supposedly made from base 4+5 stock, the decrease in wear between metals might be more than a myth. For any real test, one would have to stick with the same brand/viscosity/formulation for say 20-40K miles.... or more, then take the eng apart, and see how much wear there actually is. And do this right from day1 on a new eng.

UOA's might be only telling us part of the story...esp if there is no correlation between various labs. If the goal is to lubricate moving parts, imo, you really gotta take the eng apart to get a real analysis..... or at least stuff a camera /borescope, or similar device into the plug holes, and remove the oil pan.

As a side note, on RP's API-SN plane jane oils, only their 5W-40 contains synerlec, the other viscosity's don't.

I find it amusing that NASCAR uses 5W-20....then runs the engs at sustained high rpms...like 8200-9100. Between an oil cooler + tossing it every race, it appears to do the job.

Jimbo

 

[UnleashedBeast]

You also have to remember that less viscous lubricants release heat more rapidly, effectively running cooler than a more viscous lubricant. This means a less viscous lubricant may be slightly thicker in the engine than rated, while the more viscous lubricant may run more on the thinner side of its rating.

A new UOA from RP HPS 5W-30 is in, and confirmed....the formulation shears. RP is no longer worth the price tag. Shop elsewhere. RP specs this formulation @ 11.3 cSt @ 100*C. 1st sample sheared 25%, the second sample sheared 20%. Not acceptable for a lubricant this expensive, while boasting "true synthetic". RP jumped on the hydrocracked bandwagon.

 

[Pentalab]

You also have to remember that less viscous lubricants release heat more rapidly, effectively running cooler than a more viscous lubricant. This means a less viscous lubricant may be slightly thicker in the engine than rated, while the more viscous lubricant may run more on the thinner side of its rating.

A new UOA from RP HPS 5W-30 is in, and confirmed....the formulation shears. RP is no longer worth the price tag. Shop elsewhere. RP specs this formulation @ 11.3 cSt @ 100*C. 1st sample sheared 25%, the second sample sheared 20%. Not acceptable for a lubricant this expensive, while boasting "true synthetic". RP jumped on the hydrocracked bandwagon.

Tnx for the update on the 2nd HPS 5W-30 sample. I will ask RP tech why their megabuck HPS 5W-30 shears down to a 20 weight. Their answer should prove interesting. I have 6 qts of it left, so will use it next month.

That's a helluva lot of shear for just 5000 miles. Travis should put some more in. I'd love to know what a 3rd test would produce for results. Their is an improvement between 1st and 2nd tests...including shear.

Aside from the shear issue. How does the rest of the 2nd test stack up against other oils ??

BTW.. nowhere on RP's site does it say or depict what the cSt @ 100C is supposed to be for any of the HPS oils. It only has that info for the API-SN plane oils. Did Blackstone test a virgin sample of the HPS 5W-30 oil ?

Jimbo

 

[kcbrown]

You also have to remember that less viscous lubricants release heat more rapidly, effectively running cooler than a more viscous lubricant.

I'm a bit skeptical that this is why engines run cooler when running with a less viscous lubricant. Allow me to explain...

The greater viscosity of the heavier oil yields a greater oil pressure at the pump. Greater pressure translates to greater flow rate when everything else is held constant, and pressure and flow rate are linearly related (Bernoulli's Law). But since the viscosity is greater, the flow rate is reduced proportionally.

The two factors balance each other out. This makes sense when you think about it, because the oil pump is a volumetric device that is attempting to push a given volume of oil per revolution of the pump, so the speed of the pump will determine the speed of the oil.

Hence, the flow rate of the oil should remain essentially constant, independent of viscosity, at a given engine speed. But the heat transfer rate between the oil and the engine is dependent upon the flow rate and the heat transfer coefficient. And since the flow rate is fixed, the heat transfer coefficient is the only variable left.

Is there any evidence that the heat transfer coefficient varies with viscosity, such that the greater the viscosity, the lower the coefficient? I doubt it.

So given the above, the main reason you get greater heat out of an engine that's running a more viscous oil is that the engine has to produce more force to pump the oil at the same flow rate. More force means more energy required, which means greater fuel burn for a given power level and, thus, more heat production as well as greater frictional losses (since friction is proportional to the forces in play, and those are greater at higher power levels). Also, I expect that you'll see greater pumping losses with a more viscous fluid, and you'll get more heat buildup at the pump since the engine is forcing it to turn at a constant speed. Pumping losses, of course, will result in less flow at a given RPM, so you will get a bit of the effect you're talking about, but remember that we're talking about the difference in pumping losses, and I expect that to be relatively small.


To put it in perspective, running a GF-4 spec'ed 20 weight oil versus a GF-4 30 weight oil will get you a roughly 0.5% to 1% improvement in efficiency, according to this (see section 2.f. While this is a standard, it's unlikely that oils which meet or exceed that standard will do so by much). Not only is that barely measurable, it's easily within the measurement noise. You'd have to average a lot of instances to see that in the trends. A 0.5% to 1% difference when jumping a grade is not going to be noticeable in terms of the heat transfer, block temperatures, etc. You'll get far more variation than that due to variation in external conditions.

 

[UnleashedBeast]

It's not uncommon for sump temperatures to decrease when a less viscous lubricant is used. Even Dr. Haas noted the change.

BTW.. nowhere on RP's site does it say or depict what the cSt @ 100C is supposed to be for any of the HPS oils. It only has that info for the API-SN plane oils. Did Blackstone test a virgin sample of the HPS 5W-30 oil ?

Jimbo

Of course, RP doesn't post ANY information about their new reformulations. Why, because they are hiding the truth.

11.3 cSt was taken from a VOA submitted to Blackstone Labs.

 

[kcbrown]

It's not uncommon for sump temperatures to decrease when a less viscous lubricant is used. Even Dr. Haas noted the change.

Of course. But as I explained, that's almost certainly because with the more viscous oil, the engine is having to use more energy in order to produce the same amount of power at the crank. That excess energy is going into counteracting the additional friction losses associated with having to push around a more viscous fluid through the engine. Those friction losses are from the oil itself. It's not that the lower viscosity oil is any better at transferring heat, it's that there's less heat for it to transfer to begin with, because the engine doesn't have to work as hard to move it around.

Moreover, I think you'll find that it's not just the oil in the sump that's warmer with a higher viscosity oil, it's the engine as a whole, in part because of the extra frictional heat transferred to it from the oil, but mainly because of the extra waste heat from the additional combustion that is necessary to counteract that friction.

So the oil is warmer not only because there's a slightly greater amount of friction within it, but also (and mainly) because the engine itself is warmer from having to produce more energy.


Remember that internal combustion engines are not terribly efficient, averaging around 20%. That means that 80% of the energy produced by the engine is expelled as waste heat. So whatever the frictional loss difference due to a change of oil viscosity, you'd have to multiply it by 4 to get the resulting difference in waste heat energy produced by the engine.

Even so, the difference is minute, resulting in a difference of roughly 1% total energy consumed at most.

 

[Pentalab]

Of course. But as I explained, that's almost certainly because with the more viscous oil, the engine is having to use more energy in order to produce the same amount of power at the crank. That excess energy is going into counteracting the additional friction losses associated with having to push around a more viscous fluid through the engine. Those friction losses are from the oil itself. It's not that the lower viscosity oil is any better at transferring heat, it's that there's less heat for it to transfer to begin with, because the engine doesn't have to work as hard to move it around.

Moreover, I think you'll find that it's not just the oil in the sump that's warmer with a higher viscosity oil, it's the engine as a whole, in part because of the extra frictional heat transferred to it from the oil, but mainly because of the extra waste heat from the additional combustion that is necessary to counteract that friction.

So the oil is warmer not only because there's a slightly greater amount of friction within it, but also (and mainly) because the engine itself is warmer from having to produce more energy.


Remember that internal combustion engines are not terribly efficient, averaging around 20%. That means that 80% of the energy produced by the engine is expelled as waste heat. So whatever the frictional loss difference due to a change of oil viscosity, you'd have to multiply it by 4 to get the resulting difference in waste heat energy produced by the engine.

Even so, the difference is minute, resulting in a difference of roughly 1% total energy consumed at most.

Buried in that ferrari write up..or a link from the good Dr, to another portion of the oil discussion, he sez the difference in energy between the two extremes is 400w vs 700w. 1 hp = 746 watts, so its a miniscule amount. The Dr claims that lubrication is a result of the FLOW of oil.....but of course you require XXX psi to achieve a given flow rate with YYY viscosity. For a fixed viscosity, increase the pressure, flow rate increases = better lubrication. The DR then goes on trying to relate blood thinner's to oil in an eng. Some of it gets a bit convoluted at times. You need a minimum film of oil at higher temps..and the higher viscosity oils will provide that. Several folks who track their cars on hot days have said their oil temps have easily hit 300F....now that's a bunch. Eng coolant temps were also on the high side.
10w-40 or 10-50W plus an oil cooler was the normal setup.

Some said the CHT's and eng coolant temps + oil temps got so hot that the car would go into limp mode....shutting off every 2nd cyl. Their 'fix' was to temp remove the oem upper grille, to increase airflow. The oem upper grille on the 2010-2012 cars severely restricts airflow. I replaced mine with the 7 bar upper grille....makes a huge difference. The ceramic coated LT's and high flow cats alone will reduce eng bay temps by 40F.

Jimbo

 

[kcbrown]

Buried in that ferrari write up..or a link from the good Dr, to another portion of the oil discussion, he sez the difference in energy between the two extremes is 400w vs 700w. 1 hp = 746 watts, so its a miniscule amount. The Dr claims that lubrication is a result of the FLOW of oil.....but of course you require XXX psi to achieve a given flow rate with YYY viscosity. For a fixed viscosity, increase the pressure, flow rate increases = better lubrication.

Exactly. And the design of the oil pumps in use is such that such pressure increase happens naturally, because the pump is designed to generate a certain flow rate at a given rotational speed. This is why your oil pressures increase as you use higher viscosity oil.

And that should make it clear that higher oil pressures in your engine are not a bad thing if you're using a higher viscosity oil -- they're a good thing. The only two realistic concerns about higher oil pressure as a result of going with a higher viscosity oil are, firstly, whether or not it exceeds the pressure of the filter's bypass valve and, secondly, whether or not it exceeds the pressure that the various seals in the engine are designed to take. In the Coyote engines, neither is a concern, since these engines are specified to be used with 5W50 in the track package version.

The other concern would be cavitation in the oil pump, but that would result in a loss of oil pressure, and would be easily detected, and I expect wouldn't happen except with much more viscous oil than what is available for these cars.

The DR then goes on trying to relate blood thinner's to oil in an eng. Some of it gets a bit convoluted at times. You need a minimum film of oil at higher temps..and the higher viscosity oils will provide that. Several folks who track their cars on hot days have said their oil temps have easily hit 300F....now that's a bunch. Eng coolant temps were also on the high side.
10w-40 or 10-50W plus an oil cooler was the normal setup.

Some said the CHT's and eng coolant temps + oil temps got so hot that the car would go into limp mode....shutting off every 2nd cyl. Their 'fix' was to temp remove the oem upper grille, to increase airflow. The oem upper grille on the 2010-2012 cars severely restricts airflow. I replaced mine with the 7 bar upper grille....makes a huge difference. The ceramic coated LT's and high flow cats alone will reduce eng bay temps by 40F.

When the internal engine temperatures get that high, it's not the oil that's the cause, it's rate of heat exchange with the outside air.

The greatest amount of heat which exits the engine does so through the radiator. This avenue of escape dominates by far and, as a result, it doesn't take a lot of reduction in the cooling system's capacity to cause a massive increase in engine temperature.

Conversely, increasing the ability of the cooling system to carry away heat will yield significant improvements in engine temperature control. As you've seen yourself. Just changing the grille yielded a significant improvement for you. The exhaust change helps to reduce the engine bay temperature, but will do little to help improve engine cooling. All the ceramic headers are doing for you is keeping the heat in the exhaust system until it can exit at the tailpipe. I've got ceramic coated shorties on my Fox Body GT and they made a massive difference in engine bay temperatures. That's a good thing, as it's likely to improve the lifespan of the various plastic items in the engine bay, but if you truly want to keep the engine cool, a radiative device that is subject to the airstream is the way to go. An oil cooler that sits in the airstream will help with that. An oil cooler such as the one on the Boss 302, GT Track Package, etc., will not help with engine cooling appreciably if the main radiator is already at the limit of its cooling capability. The answer for that is to get a bigger radiator.


This (well, and the Torsen) is the biggest reason I went with the track package instead of just the Brembo brake package. The entire system has greater cooling capacity. Under extreme conditions (105 degrees at 3000 feet, the equivalent of about 117 degrees at sea level), even that might not be enough, and something like the Revan Racing radiator or the Cool Tech supplemental oil cooler might be necessary. But regardless, sufficient cooling capacity, and not a lower viscosity oil, is what will keep engine temperatures in check in demanding conditions.