Canadian winters and PHEV
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Canadian winters and PHEV
Does the GLC350e warm up the engine oil, when driving on electric? I'm worried that by running it in hybrid mode, the a cold engine will kick in with thicker oil at high speeds, and cause premature engine wear.
In Canada, the winters can get quite cold...
In Canada, the winters can get quite cold...
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From: Vancouver Island
I think there is a heat exchanger for the engine that is heated by the electric drivetrain. I want to get a technical document from M-B about this so I can learn more about it all. Turn the energy flow screen on when EV mode and show coolant temp under "engine". It's usually 50 degrees or more.
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I did a quick test myself this evening. I drove the car in electric mode for about 15 minutes and took a picture of the oil temperature (first pic below). I then put the vehicle on battery hold mode and took a picture of the oil temperature after 5 minutes of driving (second pic below). As you can see, the oil temperature was low on electric mode and increased when I turned on battery hold mode. It was about 13 degrees Celsius outside when I did this test so we will have to wait and see how it is in the winter.
Electric Mode
Battery Hold Mode (after 5 minutes of driving)
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Last edited by Bwds7; Oct 19, 2025 at 01:44 AM.
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Thanks for the replies so far.
I did a drive today. Outside air temp of 21 degrees C. Mostly city traffic for a 30 minute drive and started out with a 85% charge.
First 5 min on electric (which was defaulted)…oil temp stayed the same at 21 degrees C (which was the outside air temp).
The next five minutes, I put it in hybrid mode. Still no change in the oil temperature.
After five more minutes, I put it in Battery Hold, and immediately the engine kicked in, and the oil temperature started to rise accordingly.
Now, I’m not sure if there’s any literature out there to suggest an automatic preheating of the oil below a certain temperature.
The coolant temperature did rise slightly (about 10 degrees if I were to reckon off the scale).
I did a drive today. Outside air temp of 21 degrees C. Mostly city traffic for a 30 minute drive and started out with a 85% charge.
First 5 min on electric (which was defaulted)…oil temp stayed the same at 21 degrees C (which was the outside air temp).
The next five minutes, I put it in hybrid mode. Still no change in the oil temperature.
After five more minutes, I put it in Battery Hold, and immediately the engine kicked in, and the oil temperature started to rise accordingly.
Now, I’m not sure if there’s any literature out there to suggest an automatic preheating of the oil below a certain temperature.
The coolant temperature did rise slightly (about 10 degrees if I were to reckon off the scale).
Last edited by bigpaparay; Oct 19, 2025 at 01:46 PM.
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From: DFW
SL63
Thanks for the replies so far.
I did a drive today. Outside air temp of 21 degrees C. Mostly city traffic for a 30 minute drive and started out with a 85% charge.
First 5 min on electric (which was defaulted)…oil temp stayed the same at 21 degrees C (which was the outside air temp).
The next five minutes, I put it in hybrid mode. Still no change in the oil temperature.
After five more minutes, I put it in Battery Hold, and immediately the engine kicked in, and the oil temperature started to rise accordingly.
Now, I’m not sure if there’s any literature out there to suggest an automatic preheating of the oil below a certain temperature.
The coolant temperature did rise slightly (about 10 degrees if I were to reckon off the scale).
I did a drive today. Outside air temp of 21 degrees C. Mostly city traffic for a 30 minute drive and started out with a 85% charge.
First 5 min on electric (which was defaulted)…oil temp stayed the same at 21 degrees C (which was the outside air temp).
The next five minutes, I put it in hybrid mode. Still no change in the oil temperature.
After five more minutes, I put it in Battery Hold, and immediately the engine kicked in, and the oil temperature started to rise accordingly.
Now, I’m not sure if there’s any literature out there to suggest an automatic preheating of the oil below a certain temperature.
The coolant temperature did rise slightly (about 10 degrees if I were to reckon off the scale).
If I am interpreting your reporting so far, the outside air temperature or ambient, is the same as the oil temperature, when the combustion engine hasn’t run yet.
This would lead me to believe that the combustion oil temperature, at the time of the start, would be the same temperature as the ambient air.
In a garage, that might be above freezing during the Canadian winter.
But on the street or in the driveway, carport, what have you, a dipstick heater might be just the thing.
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Posts: 141
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Thanks for the replies so far.
I did a drive today. Outside air temp of 21 degrees C. Mostly city traffic for a 30 minute drive and started out with a 85% charge.
First 5 min on electric (which was defaulted)…oil temp stayed the same at 21 degrees C (which was the outside air temp).
The next five minutes, I put it in hybrid mode. Still no change in the oil temperature.
After five more minutes, I put it in Battery Hold, and immediately the engine kicked in, and the oil temperature started to rise accordingly.
Now, I’m not sure if there’s any literature out there to suggest an automatic preheating of the oil below a certain temperature.
The coolant temperature did rise slightly (about 10 degrees if I were to reckon off the scale).
I did a drive today. Outside air temp of 21 degrees C. Mostly city traffic for a 30 minute drive and started out with a 85% charge.
First 5 min on electric (which was defaulted)…oil temp stayed the same at 21 degrees C (which was the outside air temp).
The next five minutes, I put it in hybrid mode. Still no change in the oil temperature.
After five more minutes, I put it in Battery Hold, and immediately the engine kicked in, and the oil temperature started to rise accordingly.
Now, I’m not sure if there’s any literature out there to suggest an automatic preheating of the oil below a certain temperature.
The coolant temperature did rise slightly (about 10 degrees if I were to reckon off the scale).
Temperatures when I turned my vehicle on after sitting in -1 to -3°C for 12 hours
Temperatures after 30 minutes of driving on electric mode
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Update:
I depleted my battery and the oil temperature remained the same as it was when I turned on the vehicle. The oil only started to warm up once the ICE was running.
Question for any mechanics on this forum: is it harmful to have your engine turn on while driving with an oil temp below 5°C?
I depleted my battery and the oil temperature remained the same as it was when I turned on the vehicle. The oil only started to warm up once the ICE was running.
Question for any mechanics on this forum: is it harmful to have your engine turn on while driving with an oil temp below 5°C?
Newbie
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2025 GLC350e
Canadian winters
I live in Minnesota and have found that when temperatures below 15 F /- 9 C the vehicle automatically reverts to Hybrid and turns gas engine on and Electric mode disabled. I have not found anything in manual about this.
