williamn93

How low is considered dangerously low? My left rear tire pressure has been sitting at 25 to 26 while the other three tires were sitting at 30 to 31 for the past two weeks. The tire pressure light came on, and I've resetted it. I haven't drove much over the past two weeks; I only drive on the weekends. Should I worry that I may have damaged the wheel in any way?

dieseldoc

What wheels does your car have? Did you fill the tire with air before the reset? Did you check the tire for a leak?

williamn93

I have the regular 17 inch rims. No I didn't fill the tire with air before the reset, I just resetted it when I saw the "correct tire pressure message".

dieseldoc

I would not drive your car with a low tire. When you reset the system, it now thinks the correct pressures are what are currently in the car. You need to fill your tires to factory spec and then reset the system. I doubt you have damage the wheel but if you continue to lose air you run the risk of damaging it if you were to hit a pothole. You also need to make sure tire does not have a leak.

williamn93

what tire pressure is considered low?

Alfadude

Apparently whatever pressure your tire is at is considered low. What's so hard about just putting air in it? Why take a chance on ruining the tire? Probably haven't done any damage to the tire-yet-but why take a chance?

Look on the sticker of your gas filler door at what the pressure should be, fill your tires to that and then reset the pressures in the display to the correct amount as, like someone mentioned, you have reset the "correct" pressure to what you currently have, which is so low.

You have one tire out of four that has significantly less air than the others. I am guessing it just recently got that way. Chances are you have a slow leak in that tire. Go have it fixed because you are most likely living on borrowed tire. Most likely a nail or screw in it and what will happen is one day you will go out to your car needing to be somewhere in a hurry and you will see one of your tires flat at absolutely the worst possible time. Get it fixed!

Colin G

Buy a tire pressure gauge and gas stations have air pumps so have at it.


Your recommended pressure should be listed on the inside of your fuel cap door.


Reset once you have them all topped up to the correct pressure.

williamn93

no clue, that's pretty retarded of me honestly. Yeah I should check whether there's a sow leakage in my tire.

Alfadude

Have have had my car for about a year and a half now and I have had to have tires fixed FOUR times for things like screws and nails. I have never had a car that was so prone to picking stuff up like that. Maybe just a string of bad luck, who knows. I never have gotten stuck, but instead would lose a pound or so every day. I would just keep an eye on it until I could get it fixed. I have a compressor at home, so it is easy to do for me, but I always had an uneasy feeling until I could get it fixed because if it is losing air faster than the others, there is only one reason and it is not going to just stop out of the blue. It will only get worse. And then if you ruin a tire you might have to buy two depending on how worn the other tire is on that axle. This is the first car I have owned with the TPMS and I love it.

Adi-Benz

fun fact, you can leave the tire pressure screen on and fill your tires and it will update automatically. Learned that thanks to the cold

dieseldoc

Excellent recommendation.

ghlkal

speaking of low tire pressure ...

I test drove an E63 yesterday. Once I fired it up, it showed one tire at 20psi! I told the salesman "uh, are you sure you want me to drive it?" He said, "yeah, no problem"


While that's not dangerous necessarily, I wouldn't drive my car around like that.

LILBENZ230

The OP doesn't say what year his C300 is, so he may or may not have the display that shows each tire pressure.

However, the Benz has 2 warnings. In my experience with 09, 11, and now my 14 W204 is that if there is a slight difference, sometimes not more than a few PSI, the car will display "Correct Tire Pressure" when the ignition is switched off. There is no lit TPMS light. Resetting the TPMS system tells it these are the correct pressures.

If there is a large pressure loss, the car will display a red screen and "Check Tires" message. This one also lights the TPMS light and cannot simply be reset.