# PHEV never uses ICM **URL:** \ **Category:** General Discussion\ **Tags:** mercedes-benz\ **Created:** [July 11, 2025, 7:11pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982 "2025-07-11T19:11:39Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![David-Kirsch](https://avatars.discourse-cdn.com/v4/letter/d/ba8739/32.png) [@David-Kirsch](https://community.cartalk.com/u/David-Kirsch)\ **Post date:** [July 11, 2025, 7:11pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/1 "2025-07-11T19:11:39Z")
I have a 2025 GLC350e. This is a PHV with a 54 mile electric only vehicle. In actuality it charges to a 72 mile electric range! In any event, with the big electric only range it is entirely possible that I will go months without the ICM ever turning on. This raises at least a couple of questions: 1. it is bad for the ICM if it never turns on? What if it’s 6 mos, 9 mos, etc. 2. does this raise any issues/problems for the fuel that is in the tank for so long? 3. Are there any other issues related to infrequent ICM use that I should be aware of? Many thanks David ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [July 11, 2025, 7:14pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/2 "2025-07-11T19:14:54Z")
Some cars (Chevy Volt, for example) program ‘run time’ for the gas engine to make sure the gas doesn’t sit in the tank too long. Check your manual, see if yours does the same. If not, I’d want to use up a tank every 6 months or so, and I’d add Stabil at every fill to reduce problems. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [July 11, 2025, 8:26pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/3 "2025-07-11T20:26:05Z")
I have a PHEV that is very similar to that of the OP. While most of my daily driving is w/in the 50 mile battery radius, I purposely activate the gas engine once every two weeks or so, and I make sure to run it for at least 12 miles in order for the engine to get hot enough to “cook off” any moisture in the oil. Even with this habit of occasionally activating the gas engine, I typically drive 600-800 miles on ~6 gallons of gas. And, I still change the oil twice a year, even though the mfr specifies once per year. This regimen has worked well for me for the past 2 1/2 years. You might want to do something similar… or not. ---
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [July 11, 2025, 10:15pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/4 "2025-07-11T22:15:53Z")
I’m not specifically familiar with your vehicle, but most PHEVs will not let you run in EV long enough to cause fuel quality issues. The company I work for has PHEV models that periodically enter “Engine Maintenance Mode” where the car runs on the gas engine whether you like it or not. This forced gasoline consumption ensures you periodically add fresh fuel to the car. ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [July 12, 2025, 1:19pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/5 "2025-07-12T13:19:36Z")
At the price David paid for that vehicle why is he not asking the dealer these questions ? Also the dealer that we bought our 2024 Subaru Outback from had a program that after a couple of weeks we could return with questions or help setting things for our use and even gave us a 25.00 fuel card. ---
**Author:** ![glasspilot](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/glasspilot/32/27886_2.png) [@glasspilot](https://community.cartalk.com/u/glasspilot)\ **Post date:** [July 13, 2025, 6:11pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/6 "2025-07-13T18:11:29Z")
> [@David-Kirsch](#): > > it is bad for the ICM if it never turns on? ICM? I’ve never heard that term. In the electric world we say ICE. Internal Combustion Engine. I drive a 2017 Volt. If you go a few weeks with out running the engine you will get a message about “engine maintenance”. It will not let the gas to get old enough to go bad. ---
**Author:** ![Clueless33](https://avatars.discourse-cdn.com/v4/letter/c/dbc845/32.png) [@Clueless33](https://community.cartalk.com/u/Clueless33)\ **Post date:** [July 13, 2025, 7:53pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/7 "2025-07-13T19:53:56Z")
> [@VOLVO-V70](#): > > At the price David paid for that vehicle why is he not asking the dealer these questions ? He probably will. I just know the guys on here are very knowledgeable about cars. Doesn’t hurt to ask here. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [July 14, 2025, 4:01am UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/8 "2025-07-14T04:01:20Z")
> [@Clueless33](#): > > Doesn’t hurt to ask here. Some people don’t want to be bothered with a lot of automotive questions, they say the answers can be found elsewhere on the internet. This is akin to a private club, they only want to discuss their own vehicles, things like draining the transmission fluid on a Prius, installing a license plate bracket on a Subaru or wiper blades for the 100th time. ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [July 14, 2025, 11:47am UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/9 "2025-07-14T11:47:29Z")
ICM is used in the MB owner’s manual. ---
**Author:** ![Cavell](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cavell/32/43396_2.png) [@Cavell](https://community.cartalk.com/u/Cavell)\ **Post date:** [July 14, 2025, 1:22pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/10 "2025-07-14T13:22:33Z")
Is the word “engine” mentioned anywhere in mb manual? Only asking if the word engine is listed in any text in manual. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [July 14, 2025, 1:57pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/11 "2025-07-14T13:57:23Z")
> [@Cavell](#): > > Is the word “engine” mentioned anywhere in mb manual? The German word for engine is “motor”, so… ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [July 14, 2025, 2:37pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/12 "2025-07-14T14:37:55Z")
I guess I need to apologize for posting about my reluctance to drill holes in our Subaru Outback to mount a front plate bracket . Plus the part where Subaru Corparation and the dealer both did their part to solve the problem. ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [July 14, 2025, 2:51pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/13 "2025-07-14T14:51:38Z")
> [@VDCdriver](#): > > The German word for engine is “motor”, so Is the German word for Motor, Engine then??? How do they know if they are talking about the electric motor or ICE/ICM in a Hybrid?? (rhetorical mainly, really don’t care lol)… I guess some/most of the labor guides all say replace the motor mounts, not engine mounts, but when looking the same part up it is called an engine mount… Made it fun when training a new employee how to write up tickets using our POS (point of sale) and have to explain to them no no no, it’s called an engine mount for the part and then no no no it’s called a motor mount when looking up labor… 🤦‍♂️ ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [July 14, 2025, 2:58pm UTC](https://community.cartalk.com/t/phev-never-uses-icm/200982/14 "2025-07-14T14:58:06Z")
Well, BMW is short for “Bayerische Motoren Werke”, only recently have they been making electric motors.