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Transaxle Oil

Sat Sep 14, 2013 9:49 am

Well, I haven't managed to totally destroy my I-MiEV yet so I am off on another mission. The Transaxle in the I-MiEV uses ATF (automatic transmission fluid) as it's lubricant. I was digging through boxes of junk I have around and came across a couple of bottles of transaxle oil for use in the GM EV-1. It's a really low viscosity oil---about like water. The label says "Synthetic Motor Oil--For electric vehicles--Reduces viscous drag--Increases vehicle range". It was GM P/N 12371288 which is no longer available (except I found some in Italy for 30 euros a pint--maybe). I don't know who made this stuff, but if it worked in the EV-1, it should work in the I-MiEV. If it doesn't, I have a spare transaxle just in case. I don't know how much it will affect the range, but every little bit helps. Do enough minor changes and it might actually start to increase range.

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Re: Transaxle Oil

Sat Sep 14, 2013 10:10 am

I think you need to use the oil that the gear set is designed for. This *might* make a tiny (<1%) or it could ruin the unit.

A single aero mod would save you 10-15%.
Sincerely, Neil

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Re: Transaxle Oil

Sun Sep 15, 2013 10:04 am

NeilBlanchard wrote:A single aero mod would save you 10-15%.
If you got an extra 10% to 15% from every aero mod, it wouldn't take too many to double your range . . . . would it?

I could see that removing the outside mirrors would clean up the aero a bunch . . . . but would it really increase the range by that much? Where so we find these numbers?

I agree on the transmission oil - I'd stick with the recommended lube (maybe go with synthetic ATF) because there's little to be gained, but much to be lost

2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

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Re: Transaxle Oil

Sun Sep 15, 2013 12:44 pm

Already changed to the EV1 oil. Ran it 75 miles per hour on the freeway for 20 miles and turned around and did it again coming back. No ill effects. Transaxle nice and cool (considering) and no leaks. Hey, it's not for everyone, but I had the oil and I have a spare transaxle if I mess it up. I have had the I-MiEV transaxle apart and a S10-E (same as EV1) also apart. Very similar in design, gear diameters (therefore pitch line velocities), and number of reduction stages. I figure if GM went to the trouble to come up with this special expensive oil (and I had some) why not. Worst case, the transaxle will catch fire, lock up and burn the car to the ground on the side of the freeway---but more likely nothing will happen. It's like going to LED bulbs, a little expense, a little gain. In this case no expense and a little gain I am sure. Aero mods are the best thing on this car and that might be next---the mirrors look like they should be gone replaced by cameras. I am not a hypermiler but I am having fun with the car :P !

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Re: Transaxle Oil

Thu May 18, 2017 8:01 am

Hi Siai47, i see this old post on gm pn 12371288 ev1 gear oil. wondering if you have any more of the oil? i am looking for some and have not yet found an nos source. pls advise. thx. (1.75 qts)

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Re: Transaxle Oil

Mon Feb 26, 2018 9:57 am

Mievo's transaxle failure Seized Gearbox :shock: gave me a jolt as, once again, I had procrastinated and not checked nor changed the oil when I recently had Mitti up on jackstands when replacing the tires. Just ordered two quarts of Amsoil Synthetic Signature Series Automatic Transmission Fluid, which is probably overkill in our minimally-stressed i-MiEV. Just under $30 for two quarts on EBay, including shipping. It's specs say they meet/exceed the Mitsubishi DiaQueen SPIII SP3 Transmission Fluid requirements.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

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Re: Transaxle Oil

Tue Feb 27, 2018 12:15 pm

JoeS wrote: It's specs say they meet/exceed the Mitsubishi DiaQueen SPIII SP3 Transmission Fluid requirements.

If one were at all concerned about Warranty issues down the road :). I got the real deal - Mitsubishi DiaQueen SPIII SP3 Transmission Fluid. I got two of them through Amazon for $12.88 each shipped free from White Bear Mitsubishi online parts, in Minnesota. Coincidentally this is the same dealer that I bought the car from new!

2014 cool silver ES, acquired new 4/2015
2014 Labrador Black Pearl ES, acquired new 3/2016

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