2022 Mitsubishi Mirage "Normal" CVT Fluid Temperatures

[MrMPG]

I've been running the CVTz50 app for a while, The app considers 194F+ CVT fluid temps to be hot, Cruising 65-70mph on the highway with it being 90F+ out every day im seeing between 187F to 198F %90 of the time 203F on the high end for CVT fluid temps, Thats just normal highway cruise. Apparently anything over 194F starts to degrade/break down the fluid. The only way it stays under 194F is to limit the speeds to 55-60mph. Factory spec overheating warning is 279F which seems ludicrous to me lol. I've herd of people towing with these cars and i can just imagine the fluid boiling in the trans.

[Fummins]

What are your coolant temps compared to Cvt fluid temps? These things only have the tiny heat exchanger as far as cooling goes. Adding a Nissan type heat exchanger along with an external transmission fluid cooler might help keep temps down but you might need to run a thermostat inline if you ever get cooler temps?

[Top_Fuel]

...Cruising 65-70mph
...90F+
...seeing between 187F to 198F 90% of the time
...203F on the high end

I was wondering the same thing Fummins mentioned. Those numbers seem right in line with the coolant temps you might expect in those driving conditions...especially if the AC was running.

FYI...here's an excerpt from a Nissan Sentra TSB for CVTs that describes conditions that can lead to higher CVT temps...



So the lesson is...don't drive 70mph in the summer up a hill?!?


You need to drive your Mirage up to the Eisenhower Tunnel on I-70 in Colorado. I think that's something like a 30 mile incline. I wonder what your app would read under those conditions?

Factory spec overheating warning is 279F which seems ludicrous to me

I’ve read Subaru documents showing the CVT Fluid Temp warning light comes on at 257F (125 C). I’ve also seen 243F mentioned (Subaru Ascent) and 265F for other models. I’ve been unable to find a specific temperature mentioned in any Nissan documentation. That 279F in the Mirage is definitely the highest warning temperature I've seen...and it does sound completely crazy.

[MrMPG]

What are your coolant temps compared to Cvt fluid temps? These things only have the tiny heat exchanger as far as cooling goes. Adding a Nissan type heat exchanger along with an external transmission fluid cooler might help keep temps down but you might need to run a thermostat inline if you ever get cooler temps?

Engine coolant temps sit solidly at 194-195F even in the heat, Kind of strange to me they don't regulate the CVT temps a bit better, Id preferably like to see it about 20 degrees lower (170F) range at the hottest under normal driving conditions. Most of my commute is mostly flat ish highway at no more then 70mph, Makes me wonder how itl do during the winter. It does take quite a while for it to warm up and the cvt temps usually start to steady out at 185-190F But if you ask more of it in the heat acceleration wise it'l pass that 200F mark decently fast. I know regular autoboxes id worry if the transmission was over say 215F, I just have no idea what the "safe" range is for a CVT.

[MrMPG]

I was wondering the same thing Fummins mentioned. Those numbers seem right in line with the coolant temps you might expect in those driving conditions...especially if the AC was running.

FYI...here's an excerpt from a Nissan Sentra TSB for CVTs that describes conditions that can lead to higher CVT temps...



So the lesson is...don't drive 70mph in the summer up a hill?!?


You need to drive your Mirage up to the Eisenhower Tunnel on I-70 in Colorado. I think that's something like a 30 mile incline. I wonder what your app would read under those conditions?



I’ve read Subaru documents showing the CVT Fluid Temp warning light comes on at 257F (125 C). I’ve also seen 243F mentioned (Subaru Ascent) and 265F for other models. I’ve been unable to find a specific temperature mentioned in any Nissan documentation. That 279F in the Mirage is definitely the highest warning temperature I've seen...and it does sound completely crazy.

There's a decently steep bridge i cross over every morning, Probably %6 grade for 2 miles and it for sure starts warming the cvt up decently fast lol.

[Fummins]

I have never really tried to watch cvt temps unless trying to make sure fluid level was correct. Ignorance is bliss I guess lol
We don't have much for hills out where I live.

I used the googles and seemed to come up with random subaru posts with similar info. I don't know how hot is too hot. The fluid seems to turn dark in the Mirages much faster than the NV200 Nissans I also maintain. I haven't seen dark fluid come out of a Nissan cvt yet oddly enough....

I do know that keeping the fluid changed more often will help make these things last. I had a bunch fail at around 300k km/186k miles then started changing the fluid more often(30k miles) and now have one 2015 at 458k km(284,000miles) and lots well past 200,000miles.

[mohammad]

Engine coolant temps sit solidly at 194-195F even in the heat, Kind of strange to me they don't regulate the CVT temps a bit better, Id preferably like to see it about 20 degrees lower (170F) range at the hottest under normal driving conditions. Most of my commute is mostly flat ish highway at no more then 70mph, Makes me wonder how itl do during the winter. It does take quite a while for it to warm up and the cvt temps usually start to steady out at 185-190F But if you ask more of it in the heat acceleration wise it'l pass that 200F mark decently fast. I know regular autoboxes id worry if the transmission was over say 215F, I just have no idea what the "safe" range is for a CVT.

The CVT cooler uses coolant from the radiator. There is no cvt fluid going into a radiator. By design the cvt fluid never leaves the transmission. For obvious reasons this means that it is impossible for the CVT fluid to be cooler than coolant. It "steadys out" at approx 195f because that is approximately when the thermostat will open and coolant will circulate through the radiator and CVT heat exchanger.

Aside from installing an external radiator for CVT fluid or a dedicated coolant loop and radiator for the CVT heat exchanger, the temperature is more or less beyond our control. So i try not to think about it just like Fummins mentioned.

[inuvik]

What about putting a 180 degree thermostat replacing the 192 degree?

Motorad: 240192 OEM 192 degree thermostat

Motorad: 240180, same fit, 180 degree thermostat

[klroger]

A lower temp thermostat will reduce your MPG & maybe also the life of the engine... Not to mention less Heat in the winter as some have window defrost problems... You may even get a Check Engine Light on for a failed T-Stat... They are designed to run @ 195ish degree so you may see some funny things. If you try it, let us know as I could be ( probably ) totally wrong...

[inuvik]

A lower temp thermostat will reduce your MPG & maybe also the life of the engine... Not to mention less Heat in the winter as some have window defrost problems... You may even get a Check Engine Light on for a failed T-Stat... They are designed to run @ 195ish degree so you may see some funny things. If you try it, let us know as I could be ( probably ) totally wrong...

I'm not sure either but my 2019 OS has a 180 degree thermostat with no issues.