Tired of being reminded it's 37 degrees outside?
 

Any way to turn this warning off in the '11 X5? I can pretty much tell it's really cold out there.

With this reminder the car starts heating the outside mirrors as well. So it's not just a cold weather alert.

My 02 does this same thing.

That's been around for years... :( I wish I could turn it off in my 2008 X5!!!!

In this day and age, I can't believe that someone hasn't written software to hack the BMW software to turn things like this off. Maybe there's not the market for it or maybe it's BMW has made it too difficult. When you see how guys jailbreak iOS (iPhone) releases, you have to think the capability exists...

I think it's useful- in rural areas, temps can vary and change within a few km. There might be ice that forms in shaded areas even though the outside temp is 3°C.

Not sure when BMW started doing it but my '89 325i had the alert too, it was just a little more primitive than the snowflake graphic.

i'm just pretty much F'n sick of cold weather. it was 61 degrees yesterday, high of 38 for tomorrow. our average temp for december was easily 15-18 degrees below normal.

time to move further Southernly. :yikes:

i heard it is due to global warming ... :wow: i mean, quite inconvinient reality ... :rolleyes:

:iagree::iagree::iagree: I find it is useful reminder of potential black ice... My wife knows about it, too!

Don't you think 32* would be a better heads up?

Ice can form even if the outside ambient temperature is above 32 degrees Fahrenheit.

Scientifically, at 37 degrees it is possible for snowfall. It is a bit cooler up by the clouds and allows snow to form. At 37, it is not warm enough for that snow to turn into rain on the way down.

Although at 37 degrees, it is likely there won't be much accumulation since the ground is too warm. Thus the snow melts on contact forming a wet slushy surface (black ice)

The temperature of the road surface can be several degrees different than the air temperature at the location of the temperature sensor, i.e., the temperature display is not the road surface temperature.

Hence the signs you see which say:

http://lifeandtheology.files.wordpre...baldwinnc1.jpg

Even though I am sure the temperature displayed in the dash will not change on the bridge.

Precisely! The wind blowing over and under the bridge caused a wind chill and can freeze water on the bridge surface when the actual air temp is > 32.

I'd bet if the wind is high enough, and the bridge long enough, it might drop a degree or 2.

Several years back in an E39 M5, I ran into a hail storm in May on a road out in the country. It lasted 10-15 minutes and there was no where I could go. The road became covered with hail marbles, was slick as heck, and the temp display dropped from 70 to 35!!! I got the ding. I finally managed to find an awning and pulled off the road under cover. The lot was so slick, I could barely make it back on the road after it passed. The end result was a $2000 Dent Wizard bill.
NationWide processed several 1000 claims that day!

Wind chill isn't a real temperature; it isn't actually any colder than the ambient temperature. It is a virtual temperature that relates to how cold it feels on your skin. Cars and roads don't experience wind chill.

The 3C buffer simply allows for the risk that roads may be colder than ambient, and thus still have ice on them.

Most new cars these days have this warning. I had a 2010 GM Equinox rental a while back which also had this warning.

we got that same storm in Raleigh also, not quite as severe but i had sleet in the yard. freaky.

i'd swear that today when i got the chime, the readout said "temp is 30" :dunno:

No, it will not freeze above 32 if the bridge temperature is above 32, and the bridge temperature will not be 32 or below unless the air temperature hasn't been 32 or below. Heat will never flow from a lower temperature body to a higher temperature body no matter what the wind speed is.

:iagree:

Precisely.

But if the temp was below 32 (over night) and the water on the bridge froze, the next morning, the air may be above 32 but the water on the bridge is still frozen.

We both pointed out that there could be ice from the bridge and the air being colder overnight, and the bridge not having warmed up to ambient air temperature yet.

The water on the bridge isn't freezing in that case, it is melting. It just hasn't melted fully yet. And the wind has no effect.

Correct. I agree completely.

As I said, the "early" temperature warning is because the road temperature may be different from the air temperature flowing past the temp sensor in the vehicle.

But I would note that if the wind speed is high, the bridge might also warm-up faster than the other road surface, e.g., a 30 mph wind at 34 degrees would likely warm-up the bridge faster than the road surface on land.

So you never know which way it could go, hence the "safety margin" in the temperature warning threshold.

Minor point, but the wind can speed-up the heating or cooling of any object, just not as much as the human wind chill factor would suggest, e.g., take two 70 degree steel rods and put them in 32 degree air, one in still air and the other in a 30 mph air flow, and the one in the 30 mph air flow will cool down faster due to more convective heat transfer. (Remember the old threesome, Convection, Conduction, and Radiation?)

The key thing is that in either case, neither rod would go below 32 degrees, one would just get there faster, while the human wind chill factor is always lower than the air temperature when the wind speed is above zero.

As an aside, Heat Transfer is important enough and complex enough that when I got my Mechanical Engineering degree many years ago, there was a five-day a week course called "Heat Transfer" everyone had to take, and it was considered to be one of the hardest courses, exceeded in difficulty only by Fluid Dynamics and Thermodynamics.

Point taken. The wind has no effect on the end temperature, only the speed at which something gets there. It can't cool below the ambient, as you said. Wind chill is often quoted in posts about battery problems or low temperature oil flow. It just doesn't come into play, unless you are walking home without a hat after your X5 wouldn't start.

I enjoyed the heat transfer courses at university. I remember an assignment to figure out the heat balance of an automotive disk brake using finite element analysis. Came in handy many years later for discussions about drilled rotors. I never minded thermodynamics. Fluid mechanics, on the other hand, was brutal. I also recall a fourth year controls course that was a little abstract.

I've only seenthis alert go off once in the 3 BMW's I've owned :nanana:

You are a better man than I... I strongly disliked mine.

My understanding is that bridges and overpasses do not have the insulating "solid earth" underneath them that would otherwise retain some heat. Thus, a warning that air temps are near freezing is prudent, since overpasses can have slick spots. These surfaces are likely to freeze first and are often pre-treated the most by road crews.

Yup. And for the same reason the bridges can warm-up sooner as well.

So basically we all agree on the same thing and have said the same point about 20 times. Awesome!

At least we aren't arguing...

...Sorry, I had to.

^ shut the hell up! You're wrong!


:D

You can't.

reach up under the dash and start pulling wires, cut until it stops. easy enough, problem solved.

While driving or while stopped?

hhmmmnmnm, i suppose that would depend on your level of ambulatory dexterity with a pair of Dyke pliers. :cool:

What about reverse? I suppose if you have a backup camera it could be doable.

nice try newb, but you obviously missed the thread where i called anyone using the back-up camera a f**.

don't you have a driveway to shovel or maybe a paper route to tend to?

go away Yankee. get back to the books, that Ivy League education your daddy is paying for demands your attention. :stickpoke