[hl0m4n]

so today it was freezing in the morning (6am), and when i left the gym, body still warm, i open my door and sit on the cold leather seat, with the back of my shirt wet, and i hate that cold shiver feeling you get. so when im driving back home i remembered we have a heat function with a timer on the i-drive.

but i asked myself, if i set the time to 5 minutes before i leave the gym, the engine is cold after a 2 hour work out. so where does the heat blow from, how does the engine produce heat?

i know in the aston martins you can set a timer and the engine will run and then blast the heat or a/c if desired.

any thoughts?

[Herknav]

I don't think it produces heat if there isn't any to produce... it only uses residual.

Why not shower and change at the gym? That way you keep from getting nasty body fluids all over your interior...

[Eazyrock]

Or change your shirt..

[jngjng72]

I believe that the residual heat only works up to 15 minutes after you turn off the engine.

"The heat stored in the engine is used to heat the passenger compartment, e.g. while stopped at a school to pick up a child. The function can be switched on when the following conditions are met: up to 15 minutes after the engine has been switched off, while the engine is at operating temperature, as long as battery voltage is sufficient, at an outside temperature below 77F. The LED is lit when the function is on."

[hl0m4n]

i put my jacket i wear when entering in the morning ontop of my seat but the cold inside plus cold seats still gets to me.

changing shirt is a good idea but i take a shower when i get home and no need to put two shirts in the laundry. and for taking a shower there im shy of being in the nude .

that is what im thinking too. if there is no heat, where does the heat, if any, come from? so the use of the timer i guess is for short period of time after you turn off the car?

[anerbe]

certain cars have a PTC heater in the HVAC ducts that will provide electrical heat in cold start conditions.

This car I believe does not have this features.

[335i4u2nv]

ya man ur destroying ur interior with ur nasty sweat and funk... id beat ur azz in my car like that.

jk

[danimal]

With leather or leatherette, I wouldn't worry about getting a little sweat on the seats. They're easy to clean and they're not really absorbent (at least leatherette isn't). Anyway, when it's hot and humid in the summer, tell me you're not going to get sweat on the seats anyway! If that were true, there wouldn't be all these threads about "swamp butt" and "swamp back"

As for heat, I don't know how long heat will be produced after cutting the engine. I do know if I park my car in the garage in moderate to warm weather, the hood will still feel warm for a lot longer than 15 minutes after I cut the engine--at least an hour if not more. But it only gets down into the 40's here, so I can't test what it does in really cold weather.

Sounds like the OP should test this out and report back.

-Dan

[aspiring335]

Kind of off topic, but has anyone owned an Audi with the solar sunroof option? Does it heat the car in cold weather as well as cool it in hot weather?

I used the residual heat function quite a bit when I was living in Calgary and sometimes had to contend with temperatures of 25 below or worse. It's pretty effective for short periods of time (e.g. when you're parked at the grocery store), but it's not going to keep the car warm for two hours.

[Zephyr15]

Originally Posted by hl0m4n

so today it was freezing in the morning (6am), and when i left the gym, body still warm, i open my door and sit on the cold leather seat, with the back of my shirt wet, and i hate that cold shiver feeling you get. so when im driving back home i remembered we have a heat function with a timer on the i-drive.

but i asked myself, if i set the time to 5 minutes before i leave the gym, the engine is cold after a 2 hour work out. so where does the heat blow from, how does the engine produce heat?

i know in the aston martins you can set a timer and the engine will run and then blast the heat or a/c if desired.

any thoughts?

It sounds to me like you're confusing the residual heat function with the programable vent settings.

[anderson007]

Indeed, the settings in the I-drive are for time venting nothing to do with heating. The residual heat can only be switched on when leaving the car, and will keep it warm for about 45 minutes.

[karliejai]

try it next time... if u car is cold, the rest wouldnt work.

[AltecBX]

30 Mins max.

[Roowah]

The heat at rest function is a great feature that I use constantly on these very cold days. It's great to come back to a toasty car after getting out for 20 minutes. It does shut off automatically after awhile and it only uses the residual engine heat.

[gloster]

+1 I've used the heat at rest a couple times while waiting to pick up my kids. Engine off but heat at rest on is a peaceful way of waiting.

[SoYank]

There are two functions related to this discussion that seem to be confused with one another.

• The Residual Heat (REST button) only works if the engine has been running long enought for it to get warm. When you need to go into a shop for just a few minutes, like at a convenience store, you turn the engine off and press the REST button. There will be heat flowing through the vents derived from the residual heat from the engine. The longer you're absent, the cooler the air will be as the engine cools off.
  
• The Parked Ventilation system will turn on the fan full bore at a specified time for thirty minutes in any 24-hour period. It does not heat or even cool the air, it only circulates it. It is most useful on warm days to draw cooler outside air into the car to lower the temperature caused by the sun heating the car.

Both functions are described in the owner's manual.

[johnc_22]

I used this feature the other day when I wanted to condition my seats. It was in the low 40's in Atlanta and otherwise the seats would have been stone cold but I turned on the rest feature after running a bunch of errands, left it for 10 minutes and the car was toasty when I went to treat the seats.

[Skeeter44]

I used this function to good effect when I went to the grocery store yesterday morning (it was 14 degrees). My car was warm from my garage but 30 minutes in the store would normally have made the interior quite cold but with the rest function it instead stayed quite warm.

[purplewidow]

sweat it a killer for the seats i know people who have white stripes that you can't rub off from sweat in there m3...the function in the idrive ventilates the car..it doesn't heat it...the rest feature works for 15 mins or so..otherwise it would drain the battery dead!!!!

[danimal]

Originally Posted by gloster

+1 I've used the heat at rest a couple times while waiting to pick up my kids. Engine off but heat at rest on is a peaceful way of waiting.

If you're actually waiting in the car, you really don't need REST. Just turn the engine off but leave the fob in the dash (or nearby if you have Comfort Access). The purpose of REST is so you can run the climate control while you (and the fob) are away from the car. (Not that it hurts to use REST if you are in the car--I'm just saying, you can do what you described in any car.)

-Dan

[wrickem]

When I first got my car, I thought the "rest" function was about the dumbest thing ever. Now that it's cold, I use it at the gas station when I am sitting there waiting to be filled up. It's great!

[danimal]

Originally Posted by purplewidow

sweat it a killer for the seats i know people who have white stripes that you can't rub off from sweat in there m3...the function in the idrive ventilates the car..it doesn't heat it...the rest feature works for 15 mins or so..otherwise it would drain the battery dead!!!!

Does the M3 have Alcantara on the seats or is it just pure leather? Seems like leatherette would be the least likely to stain.

All REST does is run the fan...it would take a lot longer than 15 minutes to drain the battery doing that.

-Dan