Hi,
This is just an introduction to a report on boron CLS effects in a 1.5L, NHW11 (2001-03) Prius. It includes a test protocol to measure the engine fuel consumption after making a change in the engine oil lubrication.
The protocol is to start the car and shift into "N" a few seconds after the engine is running on its own. I'm using our 1.5L, NHW11 which shares the same engine as the NHW20 Prius, 2004-09, and AutoEnginuity and OBD scanner to record the data:
The key data are: coolant temperature, engine rpm, ignition timing and mass air flow (MAF) and here is the configuration of each run:
The next charts compare the new oil versus the same oil with the oil additive:
There was an offset in the spark reduction to 10 degrees offset due to the 11C difference in starting temperature. Furthermore, as the engine ran, the lower heat loss due to warmer ambient temperature means then engine warmed up a little faster.
Increasing the Y-scale, show nearly identical MAF profiles except at the end where the virgin oil suggests a slightly lower fuel consumption compared to the same oil treated:
However, the oil additive instructions report that the additive takes a while to coat the metal surfaces and it suspends gunk and varnish:
Quote:
"If used when you change your oil, simply add with any premium oil. If used between oil changes, add to engine at least 1,000 miles before your next oil change. This will ensure sufficient time for boundary layer formation and bonding. Add directly to crankcase when the engine is warm, then run engine approximately five minutes."
"This treatment will remove sludge and varnish from your engine. When used in engines with over 100,000 miles, change the oil and replace the oil filter after 1,000 miles to eliminate these contaminants from your engine." - additive instructions on side of box
To understand the data, the time line was offset so the first ICE rpm drop starts at the same time reference:
The plateau of the ICE coolant occurs when the thermostat opens up allowing the rest of the coolant to flow through the engine block. Once all coolant is at the same temperature, warm-up continues. This turns out to be the best window to get reproducible, fuel consumption rates.
Changing the Y-axis scale, we see the ignition advance change occurs concurrent with the engine rpm reduction:
Again, increasing the Y-scale, the MAF lines are all but on top of each other:
There is no evidence that treating the oil had an effect during a cold-start, warm-up. This raises a question of whether or not we could detect any difference in oil friction effects.
To test the test, we compared the 0W-20, 8k service miles to the virgin, 5W-30 oil. Changing the time scale to align inflection points, we find a consistent gap between the used and new oil during warm-up:
This data set provided ~2,400 samples showing the lower fuel consuming 0W-20 with 8k service miles versus the stock, 5W-30 with 0 service miles.
Mapping the relative ratios we find the 0W-20 has about a 2% reduction in fuel consumption versus new 5W-30:
Good Prius friend, David Kelly, found a reference that 0W-20 has about 2% lower internal friction than 5W-30.
The oil additive instructions require 1,000 service miles before a second oil change to remove the varnish and gunk it releases from older engines. At that point, it should have coated the moving parts with a low friction layer. But 1,000 miles exceeds the tank capacity of our NHW11 so I'll have to run gas reference tests before and after each tank. Otherwise, there is a risk of measuring a change in winter-summer gas energy content and not the oil additive effect. Also, I didn't add the oil to a 'hot' engine so I may use the second oil change to add the remaining 8 oz.
The additive requires 1,000 miles before a second oil and filter change to remove the trapped and suspended varnish and gunk. The challenge is I had not stored two tanks, 20 gallons of gasoline, to keep the fuel constant.
Given the variation in ethanol and refinery output, gasoline does not have a constant, heat energy. Worse, this is the time refineries switch from a winter to summer blend and the gas station tanks are just a mix during the transition. So my next best alternative is to measure the change in fuel energy with each tank and use the accumulated offsets to adjust between the pre-treatment and post-treatment engine fuel consumption.
Two warm-up cycles were completed including a drive and cool-down. The series #6 is the last of the first tank and series #7 is the first of the new tank after 10-15 miles to replace the fuel in the gas lines.
The first chart shows the data adjusted so the end of "N" occurs on the right edge:
By careful timing, the starting temperatures were identical but the shift from "N" to "D" was not well controlled. However, when the thermostat opens at ~85C, there is a notch and plateau while the rest of the engine coolant keeps the engine at a constant, operating temperature:
Close examination shows the thermostat opening is an excellent candidate for a constant temperature state to use for fuel rate measurement:
We can see the fuel burn rate plateaus at these point:
So using my old eyes:
2.75 gm/sec - 1st tank, MAF rate
2.71 gm/sec - 2nd tank, MAF rate
(2.75 - 2.71) / 2.75 = 1.46% higher energy of second tank gas
I'll have to do the same calculation between the 2nd and 3d tanks . . . in about 450-500 miles or another three weeks. Then I'll have to wait to the end of the 3d tank to do the last oil change and consolidate all of the data.
One good side effect is now I have a much easier protocol to evaluate relative gasoline energy content than the earlier, hill climb tests used two years ago. Unlike the hill climb tests that run the engine at peak power levels, these tests are not affected by relative octane ratings.
Quote:
Sad to say, we had tornadoes cut up the TVA transmission lines around Huntsville and we were without electrical power for 112 hours. The test Prius is also used as our emergency generator (1kW burning 2 gallons/day) and I had to refuel from 'generic' gas stations. I was unable to factor out the different gasoline energy content.
Here is the data in graphical format:
Having throughly looked at the data and followed the vendor's recommended instructions, my observations are:
I can find no evidence of direct friction reduction of boron CLS (aka., boric acid) without taking extra steps to reduce particle suspension. The boron CLS appears to increase particle suspension and thus engine friction.
One additional observation is how the existing gunk in the engine can so quickly reduce the effect of an oil change. In effect, the 25% carry forward and engine pan material quickly brings the new oil to the same friction level as the old, particle loaded oil.
In the case of engine oil additives, I wanted to know what is going on. Unlike other additives, the science behind boron CLS (aka., boric acid) is backed by Argonne Labs research. It looked to be the first oil additive that due to the chemical action would remain after the first treatment and not get flushed out. But I knew my 2003 Prius, 138k mile Prius, would be a challenge.
Engine oil pans were once easily removed because they used a gasket but the 1.5L Prius oil pan is 'sealed'. To drop the pan, I'll need sealant and tools to remove the old sealant. When I drop the pan, I'll try to capture and quantify the amount of gunk removed. I just wish there were a practical way to make a real gasket instead of having to apply a bead of sealant. Then cleaning the oil pan like I do now with the transaxle, would be more practical.
What really irritates me is how little we know about the oil filters beyond the advertisements. Here is a part that is designed to pass all of the oil and the natural home for a micro-filtration trap. But no micro-filtration trap is going to remove a layer of gunk that I suspect is in my engine.
In my minds eye and soon enough, camera lense, is probably a layer of gunk several millimeters thick and hundreds of square centimeters, the area of the oil pan. It may be that the best practice is to have the oil pan dropped and cleaned either as a result of some threshold from oil testing or 100-150k miles.
This is actually three separate reports stitched together. I was encouraged to share it here if there are any questions or comments.
Bob Wilson
This is just an introduction to a report on boron CLS effects in a 1.5L, NHW11 (2001-03) Prius. It includes a test protocol to measure the engine fuel consumption after making a change in the engine oil lubrication.
The protocol is to start the car and shift into "N" a few seconds after the engine is running on its own. I'm using our 1.5L, NHW11 which shares the same engine as the NHW20 Prius, 2004-09, and AutoEnginuity and OBD scanner to record the data:
The key data are: coolant temperature, engine rpm, ignition timing and mass air flow (MAF) and here is the configuration of each run:
- #2 - 0W-20, Mobil 1, 8k service miles, 2 quarts were drained including filter
- #3 - 5W-30, Mobil 1, 0 service miles, 2.5 quarts were added
- #4 - 5W-30, Mobil 1, ~150 service miles
- #5 - 5W-30, Mobil 1, 0 service miles, added 8 oz additive
- #6 - 5W-30, Mobile 1, 1k service miles with additive
The next charts compare the new oil versus the same oil with the oil additive:
There was an offset in the spark reduction to 10 degrees offset due to the 11C difference in starting temperature. Furthermore, as the engine ran, the lower heat loss due to warmer ambient temperature means then engine warmed up a little faster.
Increasing the Y-scale, show nearly identical MAF profiles except at the end where the virgin oil suggests a slightly lower fuel consumption compared to the same oil treated:
However, the oil additive instructions report that the additive takes a while to coat the metal surfaces and it suspends gunk and varnish:
Quote:
"If used when you change your oil, simply add with any premium oil. If used between oil changes, add to engine at least 1,000 miles before your next oil change. This will ensure sufficient time for boundary layer formation and bonding. Add directly to crankcase when the engine is warm, then run engine approximately five minutes."
"This treatment will remove sludge and varnish from your engine. When used in engines with over 100,000 miles, change the oil and replace the oil filter after 1,000 miles to eliminate these contaminants from your engine." - additive instructions on side of box
To understand the data, the time line was offset so the first ICE rpm drop starts at the same time reference:
The plateau of the ICE coolant occurs when the thermostat opens up allowing the rest of the coolant to flow through the engine block. Once all coolant is at the same temperature, warm-up continues. This turns out to be the best window to get reproducible, fuel consumption rates.
Changing the Y-axis scale, we see the ignition advance change occurs concurrent with the engine rpm reduction:
Again, increasing the Y-scale, the MAF lines are all but on top of each other:
There is no evidence that treating the oil had an effect during a cold-start, warm-up. This raises a question of whether or not we could detect any difference in oil friction effects.
To test the test, we compared the 0W-20, 8k service miles to the virgin, 5W-30 oil. Changing the time scale to align inflection points, we find a consistent gap between the used and new oil during warm-up:
This data set provided ~2,400 samples showing the lower fuel consuming 0W-20 with 8k service miles versus the stock, 5W-30 with 0 service miles.
Mapping the relative ratios we find the 0W-20 has about a 2% reduction in fuel consumption versus new 5W-30:
Good Prius friend, David Kelly, found a reference that 0W-20 has about 2% lower internal friction than 5W-30.
The oil additive instructions require 1,000 service miles before a second oil change to remove the varnish and gunk it releases from older engines. At that point, it should have coated the moving parts with a low friction layer. But 1,000 miles exceeds the tank capacity of our NHW11 so I'll have to run gas reference tests before and after each tank. Otherwise, there is a risk of measuring a change in winter-summer gas energy content and not the oil additive effect. Also, I didn't add the oil to a 'hot' engine so I may use the second oil change to add the remaining 8 oz.
The additive requires 1,000 miles before a second oil and filter change to remove the trapped and suspended varnish and gunk. The challenge is I had not stored two tanks, 20 gallons of gasoline, to keep the fuel constant.
Given the variation in ethanol and refinery output, gasoline does not have a constant, heat energy. Worse, this is the time refineries switch from a winter to summer blend and the gas station tanks are just a mix during the transition. So my next best alternative is to measure the change in fuel energy with each tank and use the accumulated offsets to adjust between the pre-treatment and post-treatment engine fuel consumption.
Two warm-up cycles were completed including a drive and cool-down. The series #6 is the last of the first tank and series #7 is the first of the new tank after 10-15 miles to replace the fuel in the gas lines.
The first chart shows the data adjusted so the end of "N" occurs on the right edge:
By careful timing, the starting temperatures were identical but the shift from "N" to "D" was not well controlled. However, when the thermostat opens at ~85C, there is a notch and plateau while the rest of the engine coolant keeps the engine at a constant, operating temperature:
Close examination shows the thermostat opening is an excellent candidate for a constant temperature state to use for fuel rate measurement:
We can see the fuel burn rate plateaus at these point:
So using my old eyes:
2.75 gm/sec - 1st tank, MAF rate
2.71 gm/sec - 2nd tank, MAF rate
(2.75 - 2.71) / 2.75 = 1.46% higher energy of second tank gas
I'll have to do the same calculation between the 2nd and 3d tanks . . . in about 450-500 miles or another three weeks. Then I'll have to wait to the end of the 3d tank to do the last oil change and consolidate all of the data.
One good side effect is now I have a much easier protocol to evaluate relative gasoline energy content than the earlier, hill climb tests used two years ago. Unlike the hill climb tests that run the engine at peak power levels, these tests are not affected by relative octane ratings.
Quote:
Sad to say, we had tornadoes cut up the TVA transmission lines around Huntsville and we were without electrical power for 112 hours. The test Prius is also used as our emergency generator (1kW burning 2 gallons/day) and I had to refuel from 'generic' gas stations. I was unable to factor out the different gasoline energy content.
Here is the data in graphical format:
Having throughly looked at the data and followed the vendor's recommended instructions, my observations are:
- oil change particle reduction - there is strong evidence that changing the oil substantially reduces engine fuel consumption, ~2.1 gm/sec MAF.
- boron CLS - appears to accelerate suspension of particle suspension and a subsequent increased in drag, ~2.25 gm/sec MAF.
I can find no evidence of direct friction reduction of boron CLS (aka., boric acid) without taking extra steps to reduce particle suspension. The boron CLS appears to increase particle suspension and thus engine friction.
One additional observation is how the existing gunk in the engine can so quickly reduce the effect of an oil change. In effect, the 25% carry forward and engine pan material quickly brings the new oil to the same friction level as the old, particle loaded oil.
In the case of engine oil additives, I wanted to know what is going on. Unlike other additives, the science behind boron CLS (aka., boric acid) is backed by Argonne Labs research. It looked to be the first oil additive that due to the chemical action would remain after the first treatment and not get flushed out. But I knew my 2003 Prius, 138k mile Prius, would be a challenge.
Engine oil pans were once easily removed because they used a gasket but the 1.5L Prius oil pan is 'sealed'. To drop the pan, I'll need sealant and tools to remove the old sealant. When I drop the pan, I'll try to capture and quantify the amount of gunk removed. I just wish there were a practical way to make a real gasket instead of having to apply a bead of sealant. Then cleaning the oil pan like I do now with the transaxle, would be more practical.
What really irritates me is how little we know about the oil filters beyond the advertisements. Here is a part that is designed to pass all of the oil and the natural home for a micro-filtration trap. But no micro-filtration trap is going to remove a layer of gunk that I suspect is in my engine.
In my minds eye and soon enough, camera lense, is probably a layer of gunk several millimeters thick and hundreds of square centimeters, the area of the oil pan. It may be that the best practice is to have the oil pan dropped and cleaned either as a result of some threshold from oil testing or 100-150k miles.
This is actually three separate reports stitched together. I was encouraged to share it here if there are any questions or comments.
Bob Wilson
Last edited:
