Reduction Gear Oil Change - Benefits for Range

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voltamps said:
For those into LeafSpy Pro, page 4, the Motor-Inverter Temperature next to that weird "gids" name,
... What's the highest temperature you can get to on that? I just did 155F on a hot day, 70mph cruising for 12 miles. Later I may switch to a lower visc ATF fluid & see if it nudges down some.
Today, I was able to get the gear oil temperature to 150F while the motor temperature stayed around 122F. 20 mile drive, 50 mph max, outside temperature 86F and sunny. So the gear oil temperature can run higher than the motor temperature while the motor gets the benefit of cooling it seems.
 
This is a better snapshot of what is going on. You just started the Leaf, all the engine components are the same temperature as the ambient air temperature. As you drive, the Motor heats up the fastest (makes sense), followed by the gear oil and then finally the system coolant. If you continue driving at a fairly constant rate without having to stop, accelerate, etc, then the motor will reach a temperature where it will kind of stabilize and then the gear oil heats up to match this within a mile or two. Once the gear oil matches the motor temperature, provided you are still driving, the temperature will continue to rise until it stabilizes at the optimal temperature for viscosity that Voltamps mentioned earlier. So the biggest input for heat is the Motor, followed by the friction in the gear oil generated by the reduction gear. Finally, the coolant is circuiting around the motor and electronics where it will absorb heat and then channel the heat into the radiator to be carried away by whatever air flow is going on.
This picture (which I needed a 2nd cell phone to take a picture of another, :lol: ) was done at 50 mph with an outside temperature of 82F. Depending on if I was going uphill or downhill, the motor could top out at +130F uphill and then cool down quickly to the sub 120F if going downhill or level driving for a little bit. I'm going uphill in the picture.

Probe 1 (gear oil) - Temperature 153F
Probe 2 (coolant) - Temperature 88F
LeafSpy (motor) - Temperature 129F

ETdATcr.jpg
 
Sounds right. I too have noticed the LeafSpy motor temperature follows how hard the motor is working.
Today I set a personal record for high motor temp: 171F after climbing out of the Denver area into the Rocky Mountains on I-70, where it was unusually hot at about 90F air temperature. That is about the worst I can throw at it. Doing 70 mph, up-grade, hot, high altitude. I'd guess the Leaf's warning light limit is around 190F or so.

My mountain-pass ascent isn't as tough as driving up Pikes Peak, or the closer (to Denver) Mt. Evans, both at 14k ft elevation. Here is a Leaf 10 years ago participating in the Pikes Peak Hill Climb time trials annual race event, and I think they may have added some additional cooling (bigger radiator?):
nissan-leaf-pikes-peak.jpg

https://www.wired.com/2011/06/nissan-leaf-silently-scales-pikes-peak/
If I tried Pikes Peak or Mt. Evans, I might get it to 180F, guessing. I do think the I-70 long ascent was decently difficult to push it though, where I got 171F motor temp.

My other reading, at a 153F motor temperature, would be the more typical summer hiway driving for me. I don't always go up into the mountains.
Both the 153F & 171F readings are quite a bit higher than yours (knightmb's) so far anyway. Now I suspect my thicker Amsoil SS ATF could have something to do with it, not sure. I'll look to put something thinner in to see if it makes a difference.

Got the Infrared Thermometer today. Wintact WT320 ; amazon has many kinds. Cheap at $15, good for cooking, forehead fevers, transmission fluid changes on my Tiguan, etc.
It should shoot the side of the Leaf gearbox after a hot run to get some idea if there is some higher temperatures there with the thicker fluid I have now.
UAjwkbg.jpg
 
i have still not replaced my gearbox, and am running the 75w90. The noise has gotten slightly worse over the last month or so, but is still bearable. I don't have temperature sensors in the oil, but i have no significant increase in heat to report. The gearbox on a 68F day, to the left of the fill plug, reported 105F after a 20 mile drive (this was the highest temp i could measure while pointing around in the engine bay). My efficiency is also still 3.9.. so hard to say that a ton of extra drag is in the mix.

good data though knight! impressed that you could get the motor that hot :)
 
estomax said:
... running the 75w90. ....I don't have temperature sensors in the oil, but i have no significant increase in heat to report.
And really, if the Leaf itself doesn't light up the dashboard over-heat warning light, it'sbasically OK. ....

Do you do the LeafSpy thing? The Page 4 screen shot (android; iOS similar) I posted a few posts back on this thread shows the Leaf's own internal sensor reading of the important motor-electronics assembly temperature. As long as that isn't getting elevated, all is fine. ..

knightmb found that a small increase in viscosity ATF caused an extra 20F or so (more data to come on that; not conclusive yet) in the LeafSpy motor temperature.
We're all surprised by that, since Valv ULV isn't that much different (20%) in viscosity than Matic S in knightmb's gears now. True it won't melt, yet the lower that temperature can be, the better for longevity.
 
voltamps said:
knightmb found that a small increase in viscosity ATF caused an extra 20F or so (more data to come on that; not conclusive yet) in the LeafSpy motor temperature.
We're all surprised by that, since Valv ULV isn't that much different (20%) in viscosity than Matic S in knightmb's gears now. True it won't melt, yet the lower that temperature can be, the better for longevity.

The +20F is in the gear oil itself. I didn't know I could check the motor temperature in LeafSpy when I was running the ULV. Right now, I'm just getting data for the motor temperature with the Nissan Matic S (along with gear oil, coolant, etc.) When I switch back to ULV at the end of this month (glad I bought a bag of crush washers now :lol: ), then I'll finally be able to see if the ULV is running the motor cooler or just the gear oil.
 
voltamps said:
Sounds right. I too have noticed the LeafSpy motor temperature follows how hard the motor is working.
Today I set a personal record for high motor temp: 171F after climbing out of the Denver area into the Rocky Mountains on I-70, where it was unusually hot at about 90F air temperature. That is about the worst I can throw at it. Doing 70 mph, up-grade, hot, high altitude. I'd guess the Leaf's warning light limit is around 190F or so.

Now I'm curious about mine. When I run it on the Interstate @ +70 MPH for half-hour drive for example, I can easily get the gear oil (didn't know I could check the motor at the time) temperature up to the +183F range. I wonder if the motor is that hot (hotter?) or if it continues to run in a cooler range while the gear oil makes all the heat. It's going to be 91F today, good day to burn it up! :lol:
 
Ok, had some time to kill this morning...
First picture, using the Interstate and aggressive driving I was able to get the motor up to +190F and the gear oil to +187F. Outside temperature was around 88F.

Second Picture:
Interestingly, when I exit the highway and only a few seconds sitting at a stop light, the motor quickly starts to cool down (172F). The gear oil (185F)? Well to heck with that, who needs cooling for that? :lol:

Interstate driving +70 MPH (sometimes +90 MPH at burst)
MGDWLOK.jpg


Exit ramp 0 MPH
A4nP2oi.jpg
 
knightmb said:
voltamps said:
knightmb found that a small increase in viscosity ATF caused an extra 20F or so (more data to come on that; not conclusive yet) in the LeafSpy motor temperature.
We're all surprised by that, since Valv ULV isn't that much different (20%) in viscosity than Matic S in knightmb's gears now. True it won't melt, yet the lower that temperature can be, the better for longevity.
The +20F is in the gear oil itself. I didn't know I could check the motor temperature in LeafSpy when I was running the ULV. Right now, I'm just getting data for the motor temperature with the Nissan Matic S (along with gear oil, coolant, etc.) When I switch back to ULV at the end of this month (glad I bought a bag of crush washers now :lol: ), then I'll finally be able to see if the ULV is running the motor cooler or just the gear oil.

I was remembering this event that originally got me concerned about some extra gearbox heat causing (via aluminum conduction) extra motor-inverter and/or coolant probe temperatures:
.... knightmb was reading (before LeafSpy temperature; coolant probe only): "For example, if the outside temperature was 80F and you just drive around town (speeds under 55 mph) then with the ULV, the coolant temperature stays between 88F and 90F. The gear oil temperature will stay between 130F and 140F. Under the same conditions now, the Nissan Matic S is keeping the gear oil temperature between 150F to 155F and coolant temperature between 100F and 104F."
.... which was really a delta 14F difference (90F vs. 104F), using the coolant probe, not the LeafSpy motor-inverter temperature, but the two should be related, you'd think. .. If the coolant probe shows 14F diff, then maybe the LeafSpy motor-inverter temperature is delta 20F (??) Whether 14F or 20F diff, it did appear Matic S was heating up the rest of the whole shiny aluminum unit, electronics & all, a little extra compared to Valv ULV thin stuff.

But, yes, I agree just going by LeafSpy motor-inverter temperature is best from now on, compared to the coolant probe method.

Gear oil temperature is interesting to me to see if Valv ULV actually runs at a lower temperature than Matic S, which means operating hot visc is actually the same.
 
knightmb said:
First picture, using the Interstate and aggressive driving I was able to get the motor up to +190F and the gear oil to +187F. Outside temperature was around 88F.
I was only able to get 171F, gaining elevation on a 70 mph mountain pass climb, at 90F air temperature, kind of a hard slog up.
This tells me Amsoil SS, even though its a bit thicker than Matic S, doesn't seem to make the big aluminum box run hotter.

This morning, I went out in in 85F weather, 70 mph cruise, not too much uphill this time, and almost matched what knightmb was seeing the other day with some more leisurely driving in 80+ F weather there. Trying to take the different ambient temperatures between knightmb's leisurely runs & my slightly faster, slightly hotter run) into account, the Amsoil SS looks to be about matching Matic S's LeafSpy motor temperature, that's good! I got 135F vs. knightmb's 129F, and the difference can easily be accounted for by the diff driving, ambient temperatures.
 
Just to add more data to this. When *charging*, the radiator fans come on at 127F coolant temperature (gear oil happen to be exactly the same temperature). This is different than when the Leaf is in drive mode, it appears. But, when I loaded up LeafSpy and checked the motor temperature, it was showing 142F, which is close to when I was heating the entire engine block with a Heatgun while in drive mode to raise the temperature of the whole thing to 140F to make the radiator fans come on. My guess is the motor + electronics (regardless of coolant temperature) will always kick on the radiator fans for cooling once it gets above 140F. That would explain why I can capture data of the radiator fans kicking on, but the coolant temperature is well below that.
The more data I gather, the more it all starts to make sense. :D

So, it appears that once the motor + electronics breaks the 140F barrier, the cooling system goes from passive (just running the coolant pump in low mode) to more active (running the radiator fans + coolant pump on high). I think I might see where the ULV has the power saving benefit. If it can run the motor (and the gear oil itself) cooler than 140F, then the additional power of the radiator fans + coolant pump on high is not needed. All of those systems use a little chunk of power. The fans eat up +600W of power, the coolant pump (from what I could find online) uses about +150 watts on high mode. So if the motor temperature stays above 140F, you can expect almost +800W of additional power needed to keep it cooling. That's about the same savings of power from using the climate control during a trip provided it's not at the extreme of hot or cold. The efficiency savings of *NOT* using the climate control seems to be very similar to the efficiency savings provided by the ULV.

i0HQug3.jpg
 
voltamps said:
knightmb said:
First picture, using the Interstate and aggressive driving I was able to get the motor up to +190F and the gear oil to +187F. Outside temperature was around 88F.
I was only able to get 171F, gaining elevation on a 70 mph mountain pass climb, at 90F air temperature, kind of a hard slog up.
This tells me Amsoil SS, even though its a bit thicker than Matic S, doesn't seem to make the big aluminum box run hotter.
To be fair, I was running the Leaf hard on purpose, keeping up with the fast lane, in which burst of speed could hit +90 MPH at times before slowing down when coming to more dense traffic. :lol:
 
voltamps said:
This morning, I went out in in 85F weather, 70 mph cruise, not too much uphill this time, and almost matched what knightmb was seeing the other day with some more leisurely driving in 80+ F weather there. Trying to take the different ambient temperatures between knightmb's leisurely runs & my slightly faster, slightly hotter run) into account, the Amsoil SS looks to be about matching Matic S's LeafSpy motor temperature, that's good! I got 135F vs. knightmb's 129F, and the difference can easily be accounted for by the diff driving, ambient temperatures.

I just noticed, looking back at my Blackstone Lab report for the Matic S that came *out* of the Leaf before the ULV was put in a few months ago, the report showed the viscosity hitting 5.67 in the report. I looked back at your chart earlier, *new* Matic S on your chart is 5.2, so just changing out the factory fill Matic S lowers the viscosity already. So there is already a benefit with just changing out the gear oil with identical stuff, minus all the break-in gunk from the gears from the factory. The ULV might just help it along a little further with temperatures, but until I put it back in within a few weeks, I won't know what temperature the motor is operating at. It looks like changing out the gear oil after some time for the gear break will benefit all Leaf owners and with higher quality oils performing better for efficiency. I'm not ready to call it a one and done yet, but it looks like there is a good benefit to doing the change and getting a small, but permanent boost in efficiency (and as you said, less heat, less wear on the life of the parts)

Referencing from here: https://mynissanleaf.com/viewtopic.php?f=38&t=32136&start=10
 
I was able to get the radiator fans to turn on whileL2 charging. Measuring the coolant hose for discharge from the motor (end of the series string of onboard charger, DC-DC converter, inverter, and motor) that returns coolant to the radiator yielded 140 F using the Fluke infrared thermometer. The power stack and motor were all at about the same temperature. The fans just run for a few seconds as a time when the coolant discharge temperature is 140 F so that is probably the threshold. It may be a few degrees hotter the next time I charge so I will try to get more date.
 
GerryAZ said:
I was able to get the radiator fans to turn on whileL2 charging. Measuring the coolant hose for discharge from the motor (end of the series string of onboard charger, DC-DC converter, inverter, and motor) that returns coolant to the radiator yielded 140 F using the Fluke infrared thermometer. The power stack and motor were all at about the same temperature. The fans just run for a few seconds as a time when the coolant discharge temperature is 140 F so that is probably the threshold. It may be a few degrees hotter the next time I charge so I will try to get more date.

Thanks for sharing that data, it's quite useful because all I can measure is the expansion tank temperature which lags the others quite a bit. So, it seems 140F is the magic number to kick on the cooling system.
 
knightmb said:
*new* Matic S on your chart is 5.2, so just changing out the factory fill Matic S lowers the viscosity already. So there is already a benefit with just changing out the gear oil with identical stuff, minus all the break-in gunk from the gears from the factory.
Referencing from here: https://mynissanleaf.com/viewtopic.php?f=38&t=32136&start=10
Assuming Idemitsu supplies Matic S to Nissan, then kv100 5.2 is correct for new fluid. Actually, if the contract last year changed to Eneos, another Japanese oil maker, then the Nissan Matic S would be kv100 5.7 (all from tech data sheets I found). ----- 5.2 vs. 5.7, whatever it is, is ballpark "5.5", consider it.

Or, like you said, the bit of extra iron particles floating around in there (Blackstone said 120 ppm iron Fe if I recall correctly, which is kinda high, at least compared to what you get in engine oil around 30 ppm) might nudge viscosity up some.

My Amsoil SS (same visc as Redline D6) atf is about 6.3 thick in comparison, & so far I'm not seeing additional heat vs. Matic S. I might chicken out going Ultra-Low-Viscosity (ULV) 4.4 & settle for Idemitsu's MaticS at 5.2 to see if that runs cooler than Amsoil 6.3.
71RG4sK8pKL._AC_SS450_.jpg




The Matic S spec, like Dexron VI & Mercon LV specs, tells makers to target a "small" range of viscosities for new fluid, and then they all have to survive the battery of tests with their viscosity-index-improver chemicals still intact (VII), reaching a test minimum viscosity from ageing.
 
Ok, since I saw an immediately drop in efficiency and had a good week of data to collect, I didn't feel the need to wait another week to see if there was any difference. I went ahead and changed out the gear oil today from the Nissan Matic S back to the Valvoline ULV. The temperature today was similar to my other test day, no wind, EV was already ambient air temperature for everything, so I did another drive around test going the same exact route I always do so I could compare motor and gear oil temperatures again.

I am convinced that once the motor + electronics hits +140F temperature, the cooling system kicks in by running the radiator fans and coolant pump on high. This adds about a +800W additional power drain to the main battery. 800W is tiny compared to how much power it takes to push the Leaf down the road and for short trips, you won't notice much. Since that's the same difference between running the climate control on or off during the trip, it only makes a small difference on short trips.

First thing I noticed, running +50 MPH down the same route. The ULV is already running the gear oil cooler and the motor is staying well under 140F. The Nissan Matic S can do this but the gear oil temperature remains +20F hotter with Matic S. Also, the Nissan Matic S has a point where if you accelerate/stop enough, for the +50 MPH run, the gear oil heat seems to eventually make it to the motor since it is so much hotter than the motor. It will eventually heat the motor up to +140F and it seems to hold between 140F and 142F, which I guess is the cooling system working to get it down, shuts off, more heat is generated, it kicks back on again, repeat.

On the Interstate at speeds +70 MPH, the Nissan Matic S runs the gear oil at +180F, the motor basically in step with the temperature running +180F also. There is where a big difference between the two oil(s) comes out. The ULV will run the gear oil temperature between 150F to 155F, cooler temperature, sure. But... I never knew what temperature the motor was running at that speed last time. Now I know, the motor is still running *under* 140F. The gear oil temperature is actually higher than the motor temperature now, but steady. The motor temperature holds steady as well. I guess there is enough air cooling plus lower resistance of the gear oil to keep the motor from working as hard and heating up.

I'm still waiting on the results from Blackstone Labs before I make any final assessments of running ULV, but so far, everything seems to point to the direction of the ULV is saving energy and enough of it to make a tangible difference on your range and how hot your motor +electronics + gears system is running as a whole.

mnV9sCo.jpg


hYMl6qb.jpg
 
Amazing research.

This explains the efficiency boost with the reduced cooling draw. Well done. If the report comes out clean, O am game.to try the ultra low viscosity oil on my S+.

800 is not trivial. That's 12-15 watts per mile, on the highway. That costs you .25 miles per kWh at 70 and .3 at 55mph. Almost exactly what you were seeing.
 
Great write-up, knightmb.
Very cool Valv ULV gets lower gear temperatures. Wonder if Valvoline ULV is doing something to lower the gear surface friction to work with the lower viscosity , as in the chemical film (moly, boron, esters(?)) at the contacts. ..... Anyway, the results are what they are, even though I can't quite see how the "small" visc difference alone accounts for the benefits, both in range & operating temperature.

In my Leaf, I found I can reproduce the LeafSpy motor temperature of 135F arriving at the end of my "standard" 70 mph hiway run to the store. (Amsoil SS thick stuff there now.) .... That gives me a baseline to compare to changing to Valv ULV in the near future. The outside air temperature needs to be close to 85F, easy to get this summer on many days, & near-zero wind of course too is needed to keep the most important variables the same.
How much will that 135F drop using Valv ULV? I can't even guess at the moment.

On Blackstone reports, the big thing is the iron ppm. Take miles and divide by iron ppm to get a Wear Rate approximate figure.
This is what's done on ICE engine oil samples, where the iron ppm (concentration in the oil) naturally builds up over some miles. Toyota engines typically see around 2 ppm per thousand miles, and GM engines get around 3 ppm per thousand miles, something like that, so the Wear Rate depends on what machinery is there, among other variables. But a nice approx understanding can be obtained anyway.
 
Yes, preventing the 140F motor temperature (in Leafspy) from tripping the fans & coolant pump from running on high is a real savings. Thanks knightmb for uncovering that.
Not to mention just having cooler electronics & motor for long term durability. Heat is the degradation enemy of electronics.

OK, I'm going to deviate a little from using Valvoline ULV, instead trying the Mustang Mach E's Motorcraft Mercon ULV, only $6.24 per quart at a Ford dealership not far away. It has about the same "ULV" ultra-low-viscosity of kv100 4.5 vs. Valv ULV's 4.4, so I'm considering it the same.

Goal: If I can get my standard-route 70 mph run up the local highway down to an ending motor temperature of less than 135F, and I'll consider anything less than 130F to be a "win", then the experiment will essentially corroborate knightmb's finding (so far) that lower visc ATF helps a lot.
 
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