JRomulus

Interesting. I never really thought about wear for the mirrors.
I always lock mine (in a small attached garage) for security reasons but mostly because I need the extra space to walk around and between the vehicles.

spoon2000

Surely the wear on the mirrors wouldn't be any worse than on the MMI screen (here's hoping that when my screen croaks, it does so in the visible position, where it can stay indefinitely as far as I care).

I find it hard to believe that the car wastes that much battery power if left unlocked vs if left locked. That whole angle of the discussion reminds me a lot of the people who manipulate their use of the windshield wipers so as not to wear out the wiper motor...

irenesbob

Yes. One could also argue not to lock the car since it wears out the battery in the remote and because all the subsequent unlocking might wear out the door handle unlocking circuit.

snagitseven

The energy management system will cause various components to "sleep" with various modules disabled in stages regardless if the car is locked or not. The timing is dependent on the state of the battery and the length of time the car is not used. For example, the door lock proximity sensors shut down after two days of non-use. (This will require two pulls on the handle - one to reactivate the sensors and one to unlock the door). Other systems will shut down after an hour or two and as long as several days as determined by the energy management system and the battery state.
This info can be found scattered around in the manual.

superswiss

+1... These cars have a very sophisticated energy management system with one objective. To make sure there is always enough power in the battery to start the car. It doesn't matter if locked or unlocked, the energy management system will shut things down as needed to guarantee enough juice for the starter to crank over the engine. It will also do things like temporarily increasing idle rpm to charge the battery faster if needed.

manishaudi

Out of habit, I always lock my car

porksoda

Very informative and revealing response!

This may explain an issue i seem to be having that i cannot replicate, i will use this information to further troubleshoot.

I sometimes open the trunk before starting the car and i have to press the button twice, which can be explained by your explanation of proximity sensors gone into sleep. As i never lock the car in the garage this usually happens in garage and then usually if the car is armed and i open the trunk before unlocking any doors.


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As for leaving it unlocked, it is mostly for convenience, but the wing mirrors folding was just a bonus. I already was worried about the fold down of the mmi screen which gets a lot of beating from me as i sometimes make very short trips from shop to shop, and snagitseven had stated previously that the gears are now metal so if it does stop working it would be the motor and not the older plastic gears.

DB22

The folding of the MMI screen is like checking to see if the light went out in your fridge - If you are in the car then the screen is up, if you are not in the car then the screen is down. What is the point of putting it down if you are not there while it is down?

The mirrors are a different issue - if in the garage then I have more room to walk around the car if the mirrors are folded and it is less likely that I will bump into them when moving junk around in a closed space. It's the same advantage when parked and locked too.
I do, however, have more faith in the dependability of the screen than I do the mirrors but I haven't heard of issues with either since the use of metal gears.

BrentCPA

I think their concern is more about the day you get in the car and the MMI screen does NOT come up because the motor wore out . . .

FWIW my '13 was parked untouched for most of four months this winter and I was pleasantly surprised to find the battery in good health when I finally cranked it up last week. If I had known it was going to sit that long I would have had a battery tender on it but when the snow finally cleared enough to get it out of the garage it started right up. In case it matters to anyone's German mechanics it was unlocked the entire time, too.

I have had residual battery drain issues with other German automobiles so I frankly expected trouble when I realized how long it had been . . . I even grimaced when I pushed the start button but everything worked.

SILENCER

If you keep a "powder propelled projectile delivery device" in your car, certainly lock it at all times.