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BMW i3 has the AM hardware builtin but disabled it in firmware [1] due to the exact same reason: electromagnetic interferences caused poor quality of the AM rec

by devy 11y ago

BMW i3 has the AM hardware builtin but disabled it in firmware [1] due to the exact same reason: electromagnetic interferences caused poor quality of the AM reception. Obviously, AM radio on i3s can be re-enabled by firmware hacking - called "coding". [2] Even with the full metal body/frame, AM radio noise caused by EMI emitted from EV motor/circuits was still significant. I guess it's still VERY HARD to shield these EMIs. Full disclosure: I've owned BMW ActiveE and BMW i3. [1] http://www.greencarreports.com/news/1098893_bmw-i3-electric-car-quirk-no-am-radio--but-why http://www.greencarreports.com/news/1098893_bmw-i3-electric-... [2] http://www.greencarreports.com/news/1099782_bmw-i3-rex-electric-car-coding-unlocks-features-owners-want-and-may-void-warranty http://www.greencarreports.com/news/1099782_bmw-i3-rex-elect...

mikeash 11y ago
The Tesla Model S has AM. It's fun to tune the radio to an unused frequency and drive around. The radio picks up a ton of noise that sort of emulates just a little bit how a loud gasoline engine would sound. I hear that they've removed AM from the Model X.
- devy 11y ago
  The radio picks up a ton of noise that sort of emulates just a little bit how a loud gasoline engine would sound. It's the same behavior in BMW EVs(i3/i8/ActiveE/MiniE). It's not a constant noise on AM radio but really when you press the accelerator pedal hard on a quiet street could you hear the interference. BMW consider that unacceptable based on their "standards". Apparently a lot ofTesla Model S owners agree with BMW on the subpar AM radio reception and complaint on their forum[1], which was probably why AM radio removed from Model X. I do consider that a surprise feature (of emulating engine revs) albeit it's a bit annoying sometimes. [1] https://forums.teslamotors.com/forum/forums/am-radio-stations-make-whir-sound-car-accellerates-and-slows https://forums.teslamotors.com/forum/forums/am-radio-station...
  - seanp2k2 11y ago
    Funny that alternator whine is the bane of all car audio installers and a similar thing is a feature in EVs :)
- kpil 11y ago
  The Mitsubishi Outlander PHEV have an AM radio, and while there is some interference it's actually not much except on a few frequences. I admit that I spent quite a while searching for the most amount of noise.
dfox 11y ago
It's slightly non-trivial to even shield modern car audio system itself from interfering with it's own AM receiver. It involves things like dynamically scaling various clocks to be outside of the currently tuned AM channel and so on.
ars 11y ago
Do they give you some alternative way to listen to AM stations? I find AM stations very useful for traffic/weather while traveling. Also for road notices.

by devy 11y ago

mikeash 11y ago

The Tesla Model S has AM. It's fun to tune the radio to an unused frequency and drive around. The radio picks up a ton of noise that sort of emulates just a little bit how a loud gasoline engine would sound. I hear that they've removed AM from the Model X.

devy 11y ago
The radio picks up a ton of noise that sort of emulates just a little bit how a loud gasoline engine would sound. It's the same behavior in BMW EVs(i3/i8/ActiveE/MiniE). It's not a constant noise on AM radio but really when you press the accelerator pedal hard on a quiet street could you hear the interference. BMW consider that unacceptable based on their "standards". Apparently a lot ofTesla Model S owners agree with BMW on the subpar AM radio reception and complaint on their forum[1], which was probably why AM radio removed from Model X. I do consider that a surprise feature (of emulating engine revs) albeit it's a bit annoying sometimes. [1] https://forums.teslamotors.com/forum/forums/am-radio-stations-make-whir-sound-car-accellerates-and-slows https://forums.teslamotors.com/forum/forums/am-radio-station...
- seanp2k2 11y ago
  Funny that alternator whine is the bane of all car audio installers and a similar thing is a feature in EVs :)
kpil 11y ago
The Mitsubishi Outlander PHEV have an AM radio, and while there is some interference it's actually not much except on a few frequences. I admit that I spent quite a while searching for the most amount of noise.

dfox 11y ago

It's slightly non-trivial to even shield modern car audio system itself from interfering with it's own AM receiver. It involves things like dynamically scaling various clocks to be outside of the currently tuned AM channel and so on.

ars 11y ago

Do they give you some alternative way to listen to AM stations? I find AM stations very useful for traffic/weather while traveling. Also for road notices.