Reduction Gear Oil Change - Benefits for Range

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
voltamps said:
lorenfb said:
Which makes this thread laughable!
My approximations don't quite cut it, that's true. That part is laughable. There is nothing like simply trying it on the road like what knightmb & estomax are doing.

The engineering paper that showed about a 1% loss from using thicker oil kind of nails the issue, done in a real transmission. The challenge for physics modelers is to include & know about enough things to simulate it right.

.......knightmb had a good point about there being some (small??) cascading savings effect, when your battery has to provide less watts flowing out to overcome all the losses in the Road Load. Anything saved is less you have to cool with pumps and fans.

My implication was not about your approximation, but that so much effort in this thread has attempted to reduce energy losses
in the transfer case by changing oils. Your analysis was more than adequate. Most with basic engineering backgrounds would
intuitively know little would be gained.
 
voltamps said:
knightmb said:
Is there any additional energy saving when cooling the gear oil is mixed in?
Cooling the gears would make the oil stay thicker (more viscosity), and thicker oil loses even more energy. I say don't cool the oil too much since you actually want it to get as thin as possible, within limits.

knightmb said:
....the fans kick on. All of that uses energy, not sure how much, haven't measured.
Fans are wasting energy. Those fans are getting rid of the heat during charging. It's not much lost energy. Certainly losses though. Gone.

On that same note, I was once curious as to how much heat losses you get charging & discharging an Li-Ion battery. I think I found you only lose around 2% lost to waste heat, depending on the amps going in or out, but usually not much.

knightmb said:
..... avalanche effect within another system of the Leaf (cooling system) that uses a lot more power....
That's true to some extent. Think about it from the viewpoint of how much power (watts) has to flow on the wires feeding the motor. If the gearbox is more efficient, less watts are needed on those wires, less waste heat is generated. A small amount less. Same goes for better lower resistance tires, it results in the need for less watts on those wires & less heat too.

In fact, maybe the best way to look at all this is to use some hard facts we have. The Road Load, which has been measured on Leafs many times. Road Load includes the gearbox internal frictional drag, and all the dissipative energy losses up into the motor's internal windage losses.

Therefore, Road Load is great to tell us how many Watts must flow out of the battery itself !!!

Road Load at 60 MPH is 489 Newtons.
So that is 26.8 meters/second x 489 N = 13.1 kW power being drawn out of the battery at 60 mph.
Road Load from a 2013 Leaf (similar in a 2020 Leaf) from https://inldigitallibrary.inl.gov/sites/sti/sti/5737951.pdf page 5.

Routing 13.1 kW power through the gearbox, 1% of that would be 0.131 kW savings using low visc oil. Like burning a 100 watt light bulb waste at 60 mph.

Read here with regard to Li-ion battery losses; https://mynissanleaf.com/viewtopic.php?f=34&t=27600&p=585497&hilit=battery+resistance#p585497

Which then leads to why TMS is a necessity for high charge rates, e.g. Tesla.
 
lorenfb said:
My implication was not about your approximation, but that so much effort in this thread has attempted to reduce energy losses
in the transfer case by changing oils. Your analysis was more than adequate. Most with basic engineering backgrounds would
intuitively know little would be gained.
I think a lot of us, including myself know that the ULV alone won't gain much. I'm trying to figure out if the cascade effects are producing real gains for range, but I have limited data to work with, mainly my own data. That is why I'm excited to try this on an older Gen 1 Leaf with some definite before and after measurements. If the other Leaf is seeing some benefit that translates to real world gains, then it's a very cheap way to get more mileage that is permanent rather than temporary or expensive.
 
This is what steered me towards the idea after I found out the cooling fans kick on when the motor is under a high load during one of my 0 to 100 mph test. You'll have to fast forward to the 6:05 mark, that's when the fans blew the camera off it's mount while inside, during the 100 mph test. Also, the video makes the Leaf sound deafeningly loud inside. :lol: I only wanted the audio and a watchful eye on the fans, so I wasn't much into editing the video. Too bad the Leaf isn't that loud on the outside, that would certainly let everyone know you are approaching....
https://www.youtube.com/watch?v=kRKKYJCWoko
 
knight is your range increase still holding up? My average has stuck at 3.9 miles per kwh over the 3.5 that i had earlier, so up in theory over the last 1000 miles or so, but hard to say how much of it is from the warmer weather or not. Heavy foot is still in use and freeways are not too clogged so speeds are higher than pre pandemic. Gut feel wise my average may be 0.1-0.2 miles per kwh more than before at these speeds, a small delta if anything, but still fun to experiment.
 
estomax said:
knight is your range increase still holding up? .....
Sure is, a pile of data I have so far now, for one of the longer trips that has no stop lights, signs, etc.
I put the dates to it this time, easier to work with data now...
70 mph test
4/1/2021 -- 25.1 miles 3.6 miles/kWh
4/3/2021 -- 25.1 miles 3.6 miles/kWh
4/4/2021 -- 25.1 miles 3.6 miles/kWh
4/6/2021 -- 25.1 miles 3.6 miles/kWh
4/15/2021 -- 25.1 miles 3.9 miles/kWh <- Gear Oil Change *after*
4/23/2021 -- 25.1 miles 3.9 miles/kWh
4/24/2021 -- 25.1 miles 4.0 miles/kWh (windy day, probably tail wind bonus)
4/25/2021 -- 25.1 miles 3.9 miles/kWh
4/27/2021 -- 25.1 miles 3.9 miles/kWh
5/7/2021 -- 25.1 miles 3.9 miles/kWh
5/8/2021 -- 25.1 miles 3.9 miles/kWh

For the higher speed drive, seems to be about 0.2 - 0.3 increase.

For the lower speed routes, the first increase I saw was about 0.4 increase, the warmer weather has skewed it up to 0.6 increase. I keep my tire pressure as close to 42 PSI as I can, but the hotter weather means the tires can reach +46 PSI on sunny days, so it seems to have no affect on the high speed driving (which makes sense, air friction), but a bump up on the lower speed, stop and go, driving. Probably rolling resistance related at lower speeds.

It is fun to charge the vehicle to 100% and have unrealistically high GOM range estimates of +272 miles :lol:
 
This is what the Nissan EV Connect website showed after the gear oil change. :shock:

Gear Oil Change on 9th of April
OVtPZtA.jpg
 
Wow, many people reporting gains after a gear fluid change. Maybe it's the 120 ppm or so (Blackstone analysis) metal particles floating around in the old stuff, getting on the roller & ball bearings, etc., that puts up some more resistance? Those magnets don't get it all out, we know. People who put in the thicker Redline D6 have even reported some gains, wrong or right, who knows?

Ford may not want to come out and say publicly why they put in thin ULV fluid in their new Mach E, & how much Range went up due to that. People tend to criticize them for sacrificing longevity for efficiency, as what happened back when they switched about everything to 0w-20 oil.

GM's new Bolt EUV got an official EPA Range Rating of 247 miles recently, just shy of a marketing-win "250" mile round number. Since Range on the Monroney sells more new EVs, if I was at GM I would have told them to OE spec the Michelin Energy Saver A/S tires with 51 psi max sidewall pressure, and put on a new placard cold pressure on the door jam of 45 psi. I ran that 51 psi sidewall max pressure version (they make both a 44 psi & 51 psi versions in that line of tires for some strange reason) on my old '16 Focus EV, so they do exist.

-- Then of course tell them to put Dexron ULV (like Mercon ULV & Valvoline ULV thin). With both tires & the thinner fluid, they could've gotten to the psychological marketing threshold of an even 250 !
 
voltamps said:
Ford may not want to come out and say publicly why they put in thin ULV fluid in their new Mach E, & how much Range went up due to that. People tend to criticize them for sacrificing longevity for efficiency, as what happened back when they switched about everything to 0w-20 oil.
Is the new Mustang Mach E range (top end model with largest battery?) now greater than the same year Mustang gas model range? I remember that being toted around a lot on social media during the artificial "gas" shortage here in TN this week. A lot of people in my town seem to own the Mach E for some reason.
 
It didn't take me much research to find the answer! :lol: I'm assuming the Mach E would get better range at non-highway speeds, so around town driving should go quite far.

Ford Mustang Mach E (2021)
Standard - 230 Miles of Range
Max Battery Size - 305 Miles of Range

Ford Mustang (2021) - Tank Size 16 gallons
Smallest Engine Coupe 21/30 MPG (city/highway) - EcoBoost
Range could be 336 / 480

2 Door Convertible 20 / 28 MPG - Range 320 / 448

GT - 15 / 24 MPG - Range 240 / 384

Mach 1 - 15 /23 MPG - Range 240 / 368
 
voltamps said:
Wow, many people reporting gains after a gear fluid change. Maybe it's the 120 ppm or so (Blackstone analysis) metal particles floating around in the old stuff, getting on the roller & ball bearings, etc., that puts up some more resistance? Those magnets don't get it all out, we know. People who put in the thicker Redline D6 have even reported some gains, wrong or right, who knows?
I've put over +3K miles on my gear oil change so far, at this rate, come summer time when I do another change, I hope it will make a good analysis for Blackstone Lab to see if there was any reduction in metal particles (provided I'm not eating the gears), if the viscosity has changed in that time, etc. Should be interesting...
 
hmm.. i have to report an anomaly with my ULV oil change, i have started to hear a ticking sound from the transaxle, verified it is the gearbox and not the wheel bearings with a stethoscope just now. Going to get some Matic S and put that fluid back in there and see if it changes back for the better.

i pulled the fill plug and inspected the magnet, no significant buildup of any material over the last 1000 miles on it.

0ZtpTWG.jpg


Marko
 
estomax said:
hmm.. i have to report an anomaly with my ULV oil change, i have started to hear a ticking sound from the transaxle,
Yikes. That is the fear we all have in going too thin, wherever that line in the sand is. ... (((( Side note: I ran an '07 BMW 530i inline 6-cylinder on kv100 8 oil, though BMW said to use kv100 11 oil, for several years & had zero problems, so most of the time machinery can handle lower viscosity juice. (??) )))
estomax said:
Going to get some Matic S and put that fluid back in there and see if it changes back for the better.
I normally don't recommend additives to gear oil, but if it solves some small noise issues & prevents you from spending $2,000 on a new gearbox in the near future, then consider putting in some molybdenum made for this task by LiquiMoly, a decent european company, to fill in the asperities (pitting or micro-vallieys) and make the thing go another 50k miles. Either that or go a tad thicker to a kv100 7 oil in a Dexron III or Mercon V ATF fluid at walmart.
(Nissan Matic S is kv100 5.5 or so, fine, but you could go slightly thicker for a case like this if the funny sound persists.)
31ijmc0nmSL._AC_.jpg

on Amazon, or maybe napa autoparts carries it, not sure which autoparts stores have it.

estomax said:
i pulled the fill plug and inspected the magnet, no significant buildup of any material over the last 1000 miles on it.
Wow. You'd think metal would be present if noises r there, right?
 
I haven't heard any sounds such as this, I have posted up a recent video (with sound) made inside the engine compartment, sounds more like a jet engine than anything, but don't remember any ticking sounds.
https://mynissanleaf.com/viewtopic.php?f=38&t=32136&start=100#p604374
Not being a gear or transmission expert myself, a ticking sound is usually a broken gear tooth I thought?

Can you make a video (or just sound) of it?

estomax said:
hmm.. i have to report an anomaly with my ULV oil change, i have started to hear a ticking sound from the transaxle, verified it is the gearbox and not the wheel bearings with a stethoscope just now. Going to get some Matic S and put that fluid back in there and see if it changes back for the better.

i pulled the fill plug and inspected the magnet, no significant buildup of any material over the last 1000 miles on it.

Marko
 
ill get a sound of it tonight, and i think ill throw the thicker mercon v in there for the sake of science to see how much my economy worsens :) gotta keep the experiment going. you can only hear it on smooth pavement with the radio off and at speeds up to about 55 mph above which the wind noise masks it.

at the end of the day i am sample size 1 and correlation does not imply causation, so lets not jump to conclusions too fast.

Marko
 
voltamps said:
estomax said:
i pulled the fill plug and inspected the magnet, no significant buildup of any material over the last 1000 miles on it.
Wow. You'd think metal would be present if noises r there, right?

Might fragments big enough to represent a problem stand a better chance of being captured by the lower plug?
 
i will split out to another thread to not pollute this one with this sideshow. But i will get a better sound clip tonight in the garage hopefully too.
https://imgur.com/PR0Pu65
 
Nubo said:
Might fragments big enough to represent a problem stand a better chance of being captured by the lower plug?
could be. Hope not.. If it's only a faint sound, it might be solvable with slightly thicker fluid and/or molybdenum. Range won't suffer much at all with Mercon V. I'm running kv100 6.3, and mercon v is about 7.5. Supertech at Walmart or whatever brand that says mercon v works well.

The old tesla "milling sound" was bearings, for comparison, u know, when tesla changed to fancy ceramic bearings, that fiasco. Prob a different sound than this.

A guy on YouTube showed some half-peanut sized metal chunks out of a Leaf gearbox on a fluid change video. Scary but the gearbox lived on AFAIK.
 
voltamps said:
Nubo said:
Might fragments big enough to represent a problem stand a better chance of being captured by the lower plug?
could be. Hope not..

I just meant that if there were any pieces they would sink and be more likely to be found on the lower rather than top plug; i.e., observation of the fill plug might not be revealing. Of course, I hope there's no problem at all.
 
i ended up grabbing this at the auto parts store, since it was still matic S compatible at the least - Valvoline maxlife multivehicle ATF
https://sharena21.springcm.com/Public/Document/18452/9e447451-fe75-e711-9c10-ac162d889bd3/3fa3136a-09bd-e711-9c12-ac162d889bd1

it is only 5.9, couldnt convince myself to buy a heavier one right now.. but fluid change is so fast for me now i may just try a few of these fluids lol.

the noise is still there, something is clunky in there, and clunky enough that i think a thicker fluid won't cover it up. i may try legit differential oil as a last resort, or a mix of diff fluid and ATF maybe.
 
Back
Top