Hi!
I have an issue with my IS that is slowly getting very annoying. Especially now that rain and snow are appearing quite regularly. I am talking about the side mirror heating function. Or to be more specific... it turning off after x minutes (I guess around 15). Is it possible to have this always on? Or at least increase the time before it turns off automatically to something reasonable like an hour? I didn't find anything like this in the settings menus, but is it possible to have this changed by the dealer?

To be honest I don't know what Lexus were thinking when implementing this feature. On my old VW group car the mirror heating was separate from the back window heating. There I had the mirror heating switch always set to on and never had to touch it. If I wanted the back window heated I turned it on and it turned off automatically - just like it does on the Lexus. But for some reason Lexus decided to combine the back window heaters and side mirror heaters. Probably to save a few cents on a separate switch.

 

Have you noticed, how quickly the rear window and the mirrors defroster work on the Lexus? Meaning that the heating elements get a lot of power and therefore heating up really fast.
Since such heating elements are basically just thin wires, they would burn out really quickly, if you would keep them on at all times.

Usually for me, the mirrors defrost way before the rear window does.

 

I don't think they defrost any faster than on any other car. I am pretty sure that the mirrors are heated using a different method than the rear window is. So yes, I agree that constant heating of the rear window would probably not be the best idea. That's why I said that their implementation sucks.

Besides... I am not talking about defrosting here. I like this because heated mirrors prevent rain drops from sticking to the surface. So that you always have a nice clean mirror. In normal case you are left with rain spots and have to clean the damned thing manually.

 

I've had a fair share of older and newer cars and the Lexus IS amazes me, how fast the defrosters and seat heating works.
The principle of heated side mirrors is still the same - thin wire that acts as a resistor and therefore heats up when powered. You just don't see the wires, because it's a mirror.

Try some rain repellent that you use on your windshield, on the side mirrors as well. Keeps them nice and dry

 

I think a lot of manufacturers have the outside heated mirrors linked with the rear defroster. Not just Lexus. The older Toyota's, like my 85-88 Cressida, had a separated button for the outside mirror.

Just FYI, that's not the purpose of the heated mirrors. I think the owners manual states it's to defrost ice and fog of the rear glass and the mirror.

 

Heated mirror isn't for preventing raindrops from sticking on the surface. The functionality works fine and quick for me and many other users from what I can see here. The implementation is fine as well, constant burning of the coil will burn it out and can be a hazard (as its already been mentioned).

It works quick for me, not sure what else to discuss on this. Use rain-x on your mirrors for the rain.

 

Well maybe that isn't the primary function... but it's pretty good at doing exactly that.

I never even thought about using a hydrophobic coating on the mirrors. Thanks! That will definitely help.

I still think that the Germans have a better solution though - having the system always on enables you to have mirrors that stay free of raindrops and never start fogging in the first place.