Tire with ! symbol lights up after 80MPH over 10 minutes
 

Read the thread "Help me Understand TPMS" which was helpful and informative.

My 06 4.8is (88k miles & still runs great) has the dash light go on after running at 75 mph + for 10 minutes or more. Once I stop and turn the vehicle off it goes away. Does not come on at lower speeds.

I'm doing a tire swap (while at dealer for other work) to winters this Friday and looking for suggestions.

Thanks in advance -

Since you didn't tell us what you have done once you got the light, did you check the tire pressure? Confirm the tire pressure with another gauge? What was the pressure?

Fill up your tires with nitrogen and you wont have this problem anymore. Nitrogen improves the life of your tires and doesnt require refills.

^ that's not true at all. Nitrogen is the biggest scam I think to hit the auto world lately. I hope everyone remembers that atmospheric air is about 78% nitrogen anyway...the only thing the nitrogen does is it is less temperature sensitive, but that's hardly an issue with passenger cars. Race cars/race motorcycles are a bit different but still, not a big deal. Also they use it in airplane tires (when they can) because of the huge temp swings.

If your tires leak at all or the valves leak at all (whcih is normal, you generally need to add air every few months) the nitrogen won't change that a bit. Instead, you'll just be paying $10/tire to fill them and then people think they need to 'change' the air if they can't get nitrogen.

Back to OP, obviously check air pressure, but speed and time will increase pressure, not decrease it, so that doesn't make a lot of sense. Only other thing I can think of is maybe the battery is going bad and at speed the sensor has a harder time reading it? Is the system wheel specific? If so, try a quick rotate and see if the issue moves. If not, then it's more likely an issue with that sensor in the wheel well.

Actually, I believe the TPMS will alert for high pressure as well. IIRC, this past summer I had it come on after garage inflated to tire specs, not BMW. Pulled off and measured to find it too high. Let a few PSI out, cleared the alert, went on my way and haven't had it come on since.

Been years since i had to touch my tires ...

Answer:
The vehicle uses speed sensors to read tire revs. At higher speeds the difference between 2-3 psi right versus left tire, front versus rear tires will trigger the alert. Lower speeds may not trigger the delta difference. Warm tires expand, colder tires do not.

Double check the tires, make sure they are within 1 PSI of each other, reset the tire alert system, and drive. The proceedure is on the forum in multiple postings. Also in the owners manual. My took two attempts at resets.
Edit: Check tires first thing in the AM when they are STONE COLD.

Tire Rack tire pressure info - more that you would want to know. http://www.tirerack.com/tires/tirete...141110170219:s

In my experince, the system on the 4.8is (big tires) is more susceptible to alert triggers on small psi differences between the tires.

Buy a professional tire gauge (0-60 psi) instead of a pencil gauge that uses friction vs psi to display PSI. I have all the above and see a 1-2 psi difference between new.
Suggestions: http://www.summitracing.com/search/p...-and-inflators
Intercomp Racing 360060 - Intercomp Racing Glow Tire Pressure Gauges

http://static.summitracing.com/globa...60060_w_ml.jpg

I am an analog visual, so this is what I have. Others like digital...

Now back to the discussion on what air mix is inside the tires......

What the hell is winter here in the MD/VA DC area? Snow on the ground for 3 days? Solution: Stay home, drive the expendable vehicle, telecomute or what?

:bustingup
You are very amusing and probably tell everybody in excruciating detail around you what to do and share your opinion like you think everyone is stupid. Thanks for making me chuckle.

However, just to satisfy your question, the 4.8is is my expendable vehicle (I think you mean the one that is ok to drive in bad weather and if something happens to it that's ok), my other cars all have summer tires and don't get driven in bad weather with the exception of my 2011 535 which I just put some nice Conti ExtremeContact DWS all weather tires on.

I sprung for the Pirelli Scorpion Ice & Snow in the 275/40/20 and 315/35/20 (stock 4.8is sizes) which set me back $1,400 at Tire Rack a few years back for my snow tires. I tried going to all seasons and while those tires (can't remember which ones I used) were ok, the driving performance was pretty diminished summer and they were safe but not great in the winter. All seasons are a compromise and I really didn't like the way the X5 drove with those on -not a ton of grip in the summer and didn't do great in the snow. Granted, I might drive harder and go faster than some drivers so it could just be the limits were just lower with those tires.

So each spring and fall I switch between summers and winters. Maximum performance all year round, I just love the way the X5 handles and drives. I really don't ever want to get rid of the vehicle, I think it's great. This spring I'm going to buy another set of rims and save the expense related to mounting and de-mounting the tires, just swapping out the set up in my own garage instead.

For the rest of you and as many may know, there are dozens of threads on this forum that tell the virtues of running dedicated snow tires in the winter, even if you only get a bit of snow and the tread design with sipes provide tremendous grip advantage over summers/all seasons. The compounds in snow tires are designed to make them perform at their heights at cold and below freezing temperatures. All seasons are better than summers and while still a bit of a compromise work reasonably well. Driving with snow tires in the winter make the vehicle perform great in cold and below freezing temperatures and when the snow or slush hit, they do even better than all seasons.

But, running summer tires in the snow, even if for three days is very unwise. Summer tires will give nearly 0 traction in the snow and make it impossible to stop & steer safely. Driving with summer tires in the winter can work but it is important to get the tires warmed up before doing any cornering at high speeds, they just have no grip until warm. Some of my summer tires don't have grip when the temps are in the 40's until they heat up. Using all seasons in the winter in DC is really a much better decision than trying to drive with summers if there is snow.

Got the basics covered - all I did was stop the vehicle and turn it off then started it back up - the light was off.