# Thin vs Thick Discussion, Chapter 10

#### AEHaas

Motor Oil 201

I am going to again bring up the constant flow pump concept. First, it goes back to the principal that doubling the pressure of the same grade oil does not exactly double the flow but it is close. Also doubling the RPM for the same reason does not exactly double the flow but again it is close.

This shows the problem best in the Ferrari:

(A) For a 30 grade oil at normal operating temperature:
RPM....Pressure....Flow
1,000......20 PSI....1
2,000......40 PSI....2
4,000......80 PSI....4
8,000... 160 PSI....8 But: The maximum flow (because of the oil pop off bypass valve at 90 PSI ) will be 5. There are people who say the pressure is not limited and that it still increases as the RPM goes up. This is not my experience in any car I have owned. The pressure goes up to but not past the set relief pressure. If the pressure cannot increase, the flow cannot increase, plain physics.

(B) For a 30 grade oil at operating temperature
and a higher output oil pump:
RPM....Pressure..Flow
1,000......30 PSI....1.5
2,000......60 PSI....3
4,000....120 PSI....6 The maximum flow because of the oil pop off valve at 90 PSI will be 5
8,000... 240 PSI....12

If we stick with the same grade oil and increase the oil pump output we will increase the pressure and the oil flow too. If we double the oil pump output we will double the pressure and we will double the oil flow. But only to the point where the bypass pressure is reached. As shown, the high output pump is still limited to the same flow as the lower output pump when bypass is reached.

(C) For a 40 grade oil at operating temperature:
The oil is thicker, has more internal resistance and therefore requires more pressure to get the same flow. Compare this with (A):
RPM....Pressure..Flow
1,000......30 PSI....1
2,000......60 PSI....2
4,000....120 PSI....4 The maximum flow because of the oil pop off valve at 90 PSI will be 3
8,000....240 PSI....8

(D) For a 40 grade oil at operating temperature
and a higher output oil pump:
RPM....Pressure..Flow
1,000......45 PSI....1.5
2,000......90 PSI....3 The maximum flow because of the oil pop off valve at 90 PSI will be 3
4,000....180 PSI....6
8,000... 360 PSI....12

The situations (A) and (C) are close to real life, assuming no loss in the system. This is what happens when you change the 30 grade oil to a 40 grade oil in your car:

(A) For a 30 grade oil at operating temperature:
RPM....Pressure..Flow
1,000......20 PSI....1
2,000......40 PSI....2
4,000......80 PSI....4
8,000... 160 PSI....8 The maximum flow because of the oil pop off valve at 90 PSI will be 5

(C) For a 40 grade oil at operating temperature:
The oil is thicker, has more internal resistance and therefore requires more pressure to get the same flow.
RPM....Pressure..Flow
1,000......30 PSI....1
2,000......60 PSI....2
4,000....120 PSI....4 The maximum flow because of the oil pop off valve at 90 PSI will be 3
8,000....240 PSI....8

At 6,000 RPM the maximum rate of flow has been reached with the thinner oil (A). When you go to 7, 8 or 9,000 RPM you do not get any more flow. You only get a maximum rate of 5. In no car I owned has the pressure increased above the maximum relief valve pressure despite increasing RPM. The internal forces on the bearings increase but there is no additional flow of oil.

With the thicker oil you reach maximum flow at 3,000 RPM (C). Worse yet is that the maximum flow is now only 3. As we increase RPM to 4, 5, 6, 7, 8, 9,000 RPM we get no additional pressure and no additional flow, no increase in lubrication.

Next let us look at a 20 grade oil at operating temperature. We get the same flow out of our constant volume pump but the thinner oil requires less pressure to move through the system. This even goes along with the rule that we should use an oil that gives us 10 PSI per 1,000 RPM:

(D) RPM....Pressure..Flow
1,000......10 PSI....1
2,000......20 PSI....2
4,000......40 PSI....4
8,000.. ...80 PSI....8

The maximum flow rate has not been reached. If the engine went to 9,000 RPM then the flow would be 9 at 90 PSI, our maximum pressure at pop off. The engine now has 3 times the flow rate as with the 40 grade oil at full RPM. The nozzles at the bottom of each cylinder are spraying 3 times the amount of oil lubricating and cooling this section. Everything runs cooler and the separation forces in the bearings may be higher.

For engines that redline at 5,000 RPM they usually pop off the oil pressure at 40 to 50 PSI. For engines that go to 8-9,000 RPM the pressures max out at 70-90 PSI. You can now see that you can only get the maximum flow rate if you follow the 10 PSI / 1,000 RPM rule.

The winner: 0W-20 grade oil for my Maranello. I said earlier that I could have used a 10 grade oil. I actually only ran with 185 F oil temperatures around town and the pressures were similar to the 40 grade oil example in (C) above. This is why I also said that in the racetrack condition, with hotter, thinner (0W-20) oil, I may actually get the optimal results as in (D) above.

Now let us go back to the Ferrari recommended parameters in my 575 Maranello manual. It calls for 75 PSI at 6,000 RPM. The pop off pressure has not been reached. As we now increase the RPM we still get an increase in flow rate. This is what we need and this is exactly what they are recommending. We get our maximum flow at the maximum system pressure, at about the maximum engine RPM of 7,700. There is no bypassing of the oil. All oil pumped goes through the system. There is no wasted BHP pumping oil past the bypass valve back to the oil tank. It is the perfect system.

Today they are making some variable rate oil pumps. This is so they only pump what can be used by the system (still pressure limited). There will be less waste of energy to pump oil that only ends up back in the sump because it was in bypass. The pump itself may also be protected from Cavitation wear and tear.

Finally I will compare a single, 30 grade oil, at normal (212 F) and at racetrack (302 F) temperatures:

(A) For a 30 grade oil at normal (212 F) operating temperature:
RPM....Pressure..Flow
1,000......20 PSI....1
2,000......40 PSI....2
4,000......80 PSI....4
8,000... 160 PSI....8 The maximum flow because of the oil pop off valve at 90 PSI will be 5

(E) For a 30 grade oil at elevated (302 F) operating temperature. The oil is thinner at 302 F. It requires less pressure to get the same flow:
RPM....Pressure..Flow
1,000......10 PSI....1
2,000......20 PSI....2
4,000......40 PSI....4
8,000......80 PSI....8 The maximum flow because of the oil pop off valve at 90 PSI will be 9

The hotter (302 F) 30 grade oil is thinner than the cooler (212 F) 30 grade oil. It has the same flow rate in the constant volume oil pump but at a lower pressure than the oil at normal operating temperature. This allows for a doubling of the flow rate at peak RPM. The thinning of oil at higher temperatures is a benefit. You get more flow, more cooling and more lubrication.

The 30 grade oil at 302 F has the exact same flow rate and pressures as the 20 grade oil at 212 F. See (D) above. Therefore, use the 20 grade for around town driving and the 30 grade on the hot track. You get maximum flow at each situation.

For YOUR engine, substitute the actual flow at 1,000 RPM. If your engine puts out 1.5 liters/min. at 1,000 RPM it would put out 3 liters/min. at 2,000 RPM and 6 liters/min. at 4,000 RPM and so on. The maximum flow in (A) would be 7.5 liters/min. In situations (D) and (E) you would get a maximum of 13.5 liters/min.

Conclusions:
The reason that multi-grade oils were developed in the first place was to address the problem of oil thickening after engine shutdown. Over the years we have been able to reduce the amount of thickening that occurs. Never-the-less there is no oil that does not thicken after you turn your engine off. This is why we have to warm up our engines before revving them up. Engine designers always pick the recommended oil based on a hot engine and hot oil. There is no issue with oil thinning as they are both matched when hot. The problem is oil thickening when the engine cools.

Cold engine showing very high pressures because of the thickened oil at startup:

For a 40 grade oil at 75 F at startup:
The oil is thicker, has more internal resistance and therefore requires more pressure to get the same flow. And the problem is not just for the first minute after start up. Remember that oil heats up slowly so 5 minutes later we still have almost the same pressures and flow with just a little improvement.
RPM....Pressure..Flow
1,000......60 PSI....1
2,000....120 PSI....2 The maximum flow because of the oil pop off valve at 90 PSI will be 1.5
4,000....240 PSI....4
8,000....480 PSI....8

At 1,500 RPM you reach the maximum oil flow rate and if you run to 8,000 RPM it is the same rate. The flow cannot increase and it is insufficient. This is why we must wait until our oil temperature comes up to 212 F or higher. The maximum flow rate in this case will then double, up to 3. To get even more flow in our test engine you need to use a lower viscosity grade or get the engine oil to an even higher temperature..

Again, these examples are real. In all my cars the oil pressure rises linearly until the oil pump relief pressure is hit. Then there is no additional increase in pressure and there can be no additional increase in flow. When an oil is thicker by grade or by lowered temperature the relief pressure comes into play earlier resulting in limited flow. Engine damage occurs when people rev them up before the oil has warmed up to the normal operating temperature. And this damage occurs at moderate temperatures as 75 F, not even really cold temperatures.

The new stop-start engine “feature’ of many cars results in slower engine warming and has led to issues potentially causing wear, sludge, and varnish formation. New and thinner oils are being developed to protect better from these issues.

Big diesel railroad locomotive engines have been using straight 40 grade oils for years. But they have started using 20W-40 grade multi-viscosity oils and most are zinc free. Interesting that they are now concerned about thinner start up viscosities even though these engines are infrequently turned on and off.

If you have absorbed and digested the information here you should be able to pick out the proper operating oil grade for your car, be it a 30, 40, 50 or even 20 grade oil. I have always used oils that were a grade thinner than recommended even though many use a grade thicker than recommended. But I have never used the car or truck to its full capacity of power.

I showed evidence that the starting grade should always be 0 or 5 (0W-XX or 5W-XX for thicker oils). If you want the best protection and highest output from your motor use a synthetic based oil. The actual brand is not as critical as the viscosity. The rating should be the SN or SP. Change your oil every 4 - 5,000 miles if you are stressing your oil and at least every spring.

AEHaas
These chapters are based on my research, experimentation and experience.

In hydraulic systems that don’t have regulators (every engine does) doubling the flow rate can generate 4 times the pressure. The problem with “research” from behind the steering wheel is not knowing how much or when a spring loaded PRV (not a one shot pop off valve) is bypassing (regulating the pressure and impacting flow path). Also, few sensitivity parameters are linear to start with. It’s hard to gather a useable subset of numbers when you consider flow distribution to various geometry is dynamic at all times**
Therefore many industry recommendations come from advanced laboratory studies that are repeatable - and survive peer reviews.

**

With the thicker oil you reach maximum flow at 3,000 RPM (C). Worse yet is that the maximum flow is now only 3. As we increase RPM to 4, 5, 6, 7, 8, 9,000 RPM we get no additional pressure and no additional flow, no increase in lubrication.
If lubrication is sufficient at this point, does it matter?

Also seems like the conclusion has a lot of conjecture and no real solid information. I feel you are conflating myth and facts to reach a predetermined conclusion.

In hydraulic systems that don’t have regulators (every engine does) doubling the flow rate can generate 4 times the pressure. The problem with “research” from behind the steering wheel is not knowing how much or when a spring loaded PRV (not a one shot pop off valve) is bypassing (regulating the pressure and impacting flow path). Also, few sensitivity parameters are linear to start with. It’s hard to gather a useable subset of numbers when you consider flow distribution to various geometry is dynamic at all times**
Therefore many industry recommendations come from advanced laboratory studies that are repeatable - and survive peer reviews.

**View attachment 54564

I was going to use this same graph.

In chapter ten, look at the 40 grade oil at a Florida start up temperature of 75 F. If the flow at 1,500 RPM is 15 L/min., it should be 50 L/min. at 8,000 RPM. This is what your graph says the total engine flow of oil needs to be. (Yes, I know, prepositions are not good to end sentences with). When, in all my engines, the pressure maximizes at 80 or 90 PSI when the engine is not warmed up yet at around 1,500 RPM. And despite increasing RPM the pressure in the oil ways increases no further (actual data). If there is no increase in pressure there can be no increase of flow, plain physics.

More and more oil is being bypassed, after the threshold, as your graph shows as RPM increases. But your graph shows an increase in engine oil flow even as the bypass area is reached and exceeded. However, in no engine of mine is the oil pressure higher in the oil ways, after bypass is reached. So there cannot be an increase in flow into the engine.

When I start my car and drive through the neighborhood out to the main highway my oil pressure is pegged. If I pull out into the main drag and push the throttle I need more flow according to your graph but I cannot get it as the pressure does not increase with RPM until the oil temperature gets warmer and warmer. An so, as it says in my Ferrari owners manual I limit my RPM accordingly as my engine oil warms up. Ferrari wants you to keep your RPM limited until the oil reaches the full operating temperature. I believe them.

However, if I use a thinner oil the pressure relief valve will only be reached after allowing more RPM. So I will be getting the additional flow your graph indicates I need for more RPM. I am comfortable giving my engine more throttle at lower engine oil temperatures sooner. And I have demonstrated that using a thinner oil results in less wear in the Enzo. I cannot help that some people refuse to accept the actual data from the car.

As always, your application is what counts. There is no way I can heat up the Enzo oil nor use all the available HP the engine has to offer. Therefore I do not require a 60 grade racing oil.

I was not born thinking that thinner = better. I used 20W-50 in cars and motorcycles long ago when I was less educated. I thought thicker = better. I like to think I am open minded. I have been educated and followed reasearch articles. It has led to experimentation. I learned that one can optimize the oil used in engines to meet my needs. It has served me well.

One more thing. Oils are better today and few seem to be taking this into account. Though I would use an SN rated 20 grade oil in my Enzo I would not use a 30 grade SB rated oil. People are afraid of oils without Zinc. It will disappear completely some day and it is likely the newer additives will provide even better protection. You have to go with the times.

I think you would probably feel more comfortable pulling out of my neighborhood with a 50 grade oil in your engine. I feel best with a thinner oil. I have demonstrated why I feel this way so others may experiment on their own and not be stuck in the “thicker is better” groove.

AEHaas

My textbook only has 9 chapters

Another thing about the graph. If that amount of flow is required by the average engine then thicker and thicker oils at freezing temperatures would get little or no flow. It is not fair to say you need that flow and then say a nice thick oil will stick to engine parts and not fall off and that there will be plenty of flow regardless of the freezing temperatures. "Thick oil flows just as well as thin oil but lubricates better" "Regardless of the oil temperature the flow is exactly the same." I do not believe these.

AEHaas

Another thing about the graph. If that amount of flow is required by the average engine then thicker and thicker oils at freezing temperatures would get little or no flow. It is not fair to say you need that flow and then say a nice thick oil will stick to engine parts and not fall off and that there will be plenty of flow regardless of the freezing temperatures. "Thick oil flows just as well as thin oil but lubricates better" "Regardless of the oil temperature the flow is exactly the same." I do not believe these.

AEHaas
You living in Florida probably doesn't really spark your interest in cold weather (way colder than "75 F") engine starting too much, but you should read some of the threads here about low temperature pumpability, and the studies done. In those studies, as long as the oil was pumpable by the PD pump, the engine had adequate lubrication. That is the whole premise behind the "W" rating in SAE J300.

The graph posted above came up some years ago in PD pump discussions IIRC. It was use to show how the typical PD pump can supply way more flow as RPM increases then typically needed, and how the total oil flow leaving the pump flows to different areas of an engine. It doesn't mean if the actual flow is less than shown, the engine is damaged.

As mentioned many times, literally millions of vehicles each winter are started in very cold weather with oil way thicker than what you think is "too thick". And those vehicles run 100s of thousand miles.

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Did an observation just now with a 2020 Pentastar engine.
Took my same old route where the speed limit gradually goes from 30>>40>>50 mph.
At startup the oil temp was 55F and pressure was 33 psi.
It took 9 minutes for the oil temp to reach 175F and 32 psi @ 50 mph
It took (as mentioned by Dr Haas) right at 24 minutes to reach steady state of 215F at 50 mph
I drove a ways like that and oil pressure stayed at 31 psi and steady temps (all 3)
(my intent was for the variable pump to stay low stage and not bypass any oil)
So little pressure change at all driving as I normally do …

Speaking of PD pumps and how the oil pressure increases with RPM. Here is some oil pressure vs engine RPM data I collected on my Z06 awhile back. It has both a digital oil pressure and oil temperature gauge (1 PSI resolution and 1 deg F resolution). It's a 6-speed manual, so I would just cruise at a constant RPM in whatever gear appropriate. Oil temperature was 200~205F for all data points. I would hold RPM for at least 30 seconds to let the pressure stabilize. I only went up to 5000 RPM, and redline is 6200 RPM. I believe the oil pump pressure relief was around 75~80 PSI, so at redline it would probably be on the verge of cracking the pressure relief with 200F oil. The oil pressure sensor was after the filter, so add 3 or 4 PSI to the gauge reading for pump output pressure.

'Looks as your 30 grade oil is perfect for your application. You do not reach your relief pressure until you reach maximum RPM at operating temperature.

But what is the graph during a cold start up and the same RPM?

AEHaas

'Looks as your 30 grade oil is perfect for your application. You do not reach your relief pressure until you reach maximum RPM at operating temperature.

But what is the graph during a cold start up and the same RPM?

AEHaas
At cold start-up, and at low engine RPM (2500 or less), the oil pressure never goes above 65 PSI ... so it's still out of pump relief with cold oil. I don't rev any of my engines over 2000-2500 until the oil if near (above 150F) or at full operating temperature. Of course, the pump will hit pressure relief sooner with thicker oil at higher RPM ... that's why anyone who knows about engines and oiling systems won't high rev until the oil is at full operating temperature.

Remember that Mustang video I posted in one of your other threads that showed the guy revving real high with a cold engine? I'm betting the engine still didn't suffer any damage in that case. Is it good to do? ... obviously it's not. But it's not going to blow-up an engine because the PD pump, even if in relief, is still providing plenty of oil. Engine designers anticipate cold start-ups with some revs involved before the oil is warmed up (humans are operating them), and don't design engines to become damaged if the oil flow is cut back some when the pump hits relief. Some newer cars are designed to limit the max RPM until the oil warms up to a certain temperature ... but that limited RPM is still pretty high, but obviously not redline.

Things are changing. More manuals are stating that revs should be limited until the oil comes up to temperature. Engines have rev limiters to prevent higher revolutions until the engine comes up to temperature. I wonder why. Perhaps engines are damaged when the oil is too thick? Although that's just not possible according to a lot of people here.

AEHaas

Have you ever been to the drag races just to watch? On busy days, cars (lots of them street cars) are waiting in the stagging lanes for a long time, and the engines and oil cool way down. These cars are most likely running oil heavier than 0W-20. They push them in the stagging lanes, don't fire them up to move them. When it's their turn to run, they fire up, do a big burn-out, then hammer the engine at WOT and redline down the strip, and I'm sure the oil pump is in relief most of that time. These cars are repeating that many times while there, and race their cars about every weekend. They don't blow-up because the oil pump is in relief.

Have you ever been to the drag races just to watch? On busy days, cars (lots of them street cars) are waiting in the stagging lanes for a long time, and the engines and oil cool way down. These cars are most likely running oil heavier than 0W-20. They push them in the stagging lanes, don't fire them up to move them. When it's their turn to run, they fire up, do a big burn-out, then hammer the engine at WOT and redline down the strip, and I'm sure the oil pump is in relief most of that time. These cars are repeating that many times while there, and race their cars about every weekend. They don't blow-up because the oil pump is in relief.
My nephew is a drag racing engine builder and team owner. They run custom built Honda 4 cylinder NA engines where very little is left stock beyond the block. They run 10w30, but they heat it. They also heat the transmission fluid. They do all this but still don't expect the engines to last very long. I would not buy one of those street cars from those guys knowing how they treated them and expect them to go hundreds of thousands of miles.

"Have you ever been to the drag races just to watch?"

You got me on that one. But I have dragged to test different ECU programs to see what gives the best performance. Better performance = shorter run times. At the time oil was not my concern nor my department. I could not even tell you what oil we were using. I concentrated on other things. I was into the electronic engine controls.

AEHaas

One more tidbit from drag racing....My nephew says they run the oil pump at 100psi. He said the rule of thumb is 10psi per 1000 rpm. He said 100psi is their ideal pressure but that it changes with engine temp.

One more tidbit from drag racing....My nephew says they run the oil pump at 100psi. He said the rule of thumb is 10psi per 1000 rpm. He said 100psi is their ideal pressure but that it changes with engine temp.
People who modify the oil pump typically change the pressure relief spring to raise the relief pressure so the pump delivers more oil at high RPM (ie, delayed pressure relief). A higher pressure relief would also be needed if a higher volume pump was installed.

People who modify the oil pump typically change the pressure relief spring to raise the relief pressure so the pump delivers more oil at high RPM (ie, delayed pressure relief). A higher pressure relief would also be needed if a higher volume pump was installed.
Another way to increase the flow would be to decrease the resistance of the oil itself by using a thinner oil at that temperature. Interesting that they are using a 30 grade oil, a multi viscosity one at that. And they use the 10 PSI per 1,000 RPM rule of thumb.

AEHaas

Things are changing. More manuals are stating that revs should be limited until the oil comes up to temperature. Engines have rev limiters to prevent higher revolutions until the engine comes up to temperature. I wonder why. Perhaps engines are damaged when the oil is too thick? Although that's just not possible according to a lot of people here.

AEHaas
Could it possibly be the different expansion rates of the metals used in the engines? Perhaps the designers understand that metals expand/contract at different rates and design the engine to have the correct fit at operating temps. Could it also be that the additives used in the oil don't activate until they reach a certain temp. I mean come on, if you think about it one can come up with a multitude of reasons manufactures don't want you to over rev a cold engine not related to oil thickness.

This recent post of mine may show some evidence that thinner oils in high performance engines is of benefit. As most of the milage is in town there has certainly been many hours spent during the warm up period. Some have said this is worthless data but I cannot ignore it:

It may be worth revisiting this very old UOA comparison. I have not seen a similar item recently. I am giving evidence that thinner oils can be used when otherwise very heavy grades may be specified. And that thinner oils may result in much less wear than when the “recommended” oil, in the “manual” is used. Note: We live in tropical Florida.

Several things to note. We are neighbors, drove the same car (but for the milage), drove the same way in the same environment. His car had what can be considered normal wear. Yet mine had a significantly reduced wear pattern. Also, the original RLI that dropped to a 20 grade oil had more wear than the newer “Enzo” formulation. But it was still less than the 60 grade Shell oil. Maybe the sweat spot for this car was a 30 grade oil for driving in our environment.

Compared Enzo Ferrari UOA from years ago: This is my neighbor’s 2003 Ferrari Enzo with a total of 8,800 miles on the left column and my 2003 Enzo with a total of 4,400 miles on the right column (middle 2 columns, earlier UOA of my car). Both cars had about 1,400 miles on the oil. His obviously had more break-in time. He had the oil changed by the Ferrari dealer using the required 10W-60 Shell Helix Ultra Racing oil. I ran 0W30 Castrol GC in the second column, the original formula of RLI in the 3rd column and the “new and improved “ RLI “Dr. Haas Enzo Formula" in the last column.

Tested my Enzo oils by Terry Dyson. His testing counts larger particles as well as all the smaller ones so other labs may give false lower values. At no time has the oil temperature in this engine gotten above 180 F. This latest oil has been in for nearly two years but Terry Dyson said I should just keep going (and going and going). What is particularly interesting is that the original RLI formulation dropped to a 20 grade, the newer formulation did not.

Part of the original post: I believe this formulation has been perfected and am considering it’s use in all my cars. I am not sure my wife will allow such a thick oil in her Murcielago however.

OILS: ….Shell……. GC…... RLI….... RLI - “Dr. Haas Enzo Formula”
Iron___________ 32...11...7...3 (Fe in RLI VOA =2)
Chromium ____<1...0....1...0
Nickel _________2...1....0...0
Aluminum _____11...3....2...0
Copper ________25...8....4...3
Tin ___________<1...0....0...0
Silver ________<.1....0....0...0
Titanium _____<1....0....0...0
Silicon ________ 7...3....4...2
Boron ________ 1...3...16..17
Sodium _______ 8...3....10...8
Potassium ____<10...0....0...0
Molybdenum _ <5....1....2...0
Phosphorus ___1026...935…1032…698
Zinc __________ 1135...1228…1055...988
Calcium ______ 1454…167...2108…1898
Barium ______ <10....0....2....0
Magnesium __1219...526…53...19
Antimony ____<30.....0....265…271
Fuel %Vol ____<1...1.2...1.3...1.5
Flash_______not done..335..320..300
Abs Oxid _____ 34...10..127...95
Abs Nitr ______ 11....8....8....7
Wtr %vol ____<0.1…....KF=247.......KF=1063 “a little damp, but not bad”…....766
Vis CS 100C __ 15.8....11.8….8.6….9.8
Vic CS 40C___not done…66….44….48
Gly test ______NEG…..0.37 “not antifreeze”…...0…..0
TBN _________not done...7.9....5.9...6.4
TAN _________not done...1.7....1.4...1.3
Visc Index___not done…154...177...192
Soot_________not done...0....0.01....0

AEHaas