fkaufman

In the past, numerous times I have received a message that one or the other tire is low and I should check and reset the TPMS. Today I got a message that read: "Underinflated! Please check all 4 tires and reset TPMS in MMI"

I called the Audi service as I found difficult to believe that all 4 tires would go low, all at the same moment. I was told that it is caused by the dropping temperature (true enough, it is getting colder here) and I should just reset the TPMS, which I did. However, I would be much more comfortable knowing that the tire pressures are correct.

My question is this: The sticker on the door post lists the pressure for the tires. Is that pressure to be measured when the tires are cold or when they are hot?

Frank

DeerHunter

Pressures should be measured when tires are cold. And Audi is correct - pressures need to be adjusted to reflect ambient temperatures. Get a tire pressure gauge, add some air and then reset the TPMS again.

Rick Pardo

Cold. Hopefully, there's a gas station close by to get an accurate fill. You can always take the reading in your garage and adjust when you get to the air pump. Don't forget the PSI drops by at least 1 for every 10 degree drop in ambient temperature, so factor that in as well.

fkaufman

I should have paid more attention to the sticker in the car, it actually says "Cold pressure".

Fortunately I don't need to bother a gas station, have a number of compressors and accurate pressure gages on hand. I have pumped all 4 tires up this morning and reset the TPMS so all is well.

d2000one

I'm disappointed that with all the tech this car has it doesn't tell you the actual pressure in each tire. There are much much much much cheaper cars that give you that info.

a7ubercoupe

Yup, miss it too. The Chevy Volt I traded in had that info, and I always had it visible in the driver's console center front! That being said, I also heard that the readings were not necessarily that accurate? so keep that VDO gauge handy

RookieWill

I'll second that - my 08 A8 had it, and I had just assumed this would have too... I guess I was wrong

snagitseven

There are some very good reasons why Audi switched to a passive vs. direct TPMS system in 2010 for most models. Here's a lengthy thread on the topic; (note the last few posts).

https://www.audiworld.com/forums/sho...highlight=tpms