[smv]

I just realized today, after my 1st 2,000kms on my new 335i sport DHP, that I was running at 1 bar lower pressure, instead of 2.6bar all round (as noted on the placard in B column) at 1.6 bar.. Don't ask me why, this is the 1st major oversight I did to driving cars for more than 25 years... I blame it on the units used here in gas stations (psi) and instead of 38psi, I was always pumping and correcting at 26psi!!! Also I ovesighted the reading on the gauge I use to check and instead of looking at 2.6, I was looking at 1.6 bars!!!! Funny enough, the car was running very smoothly and was impressed by the ride quality of my Bridgestone RFTs, though I felt it was a bit sluggish in accelerating and the steering was heavy enough to make me wonder why this whole fuss about light steering in the F30 compared to the E90. Luckily I was making only short trips to the office, except two major highway rides. Could it be that the RFTs saved me from a major disaster, as I never felt I was running on flat tyres? And if so, have I done some major damage to them already?

Today I put the right pressures and it is a different car and ride al together. Steering is pinpoint precise and acceleration is instant. And yes, it feels lighter but not annoying, just damn precise.

So, could I have done damage to my tyres already? Thnx!

[pazzo]

Was your TPMS on?

RFT's can run pretty low, but damage can occur to the side wall supports.

[smv]

Originally Posted by pazzo

Was your TPMS on?

RFT's can run pretty low, but damage can occur to the side wall supports.

I dont know what TPMS is, if you refer to the system showing your actual pressure, no I dont have it. i have the one that tells you if your pressure is off after you reset it. Since I was resetting everytime i was correcting it, no I did not have a warning whatsoever. i am running 19" btw with mixted tyres front/rear...

[Kabrich]

Originally Posted by travelbro

I have no idea whats going on here but I think I should start learning how much air my tires need.

Perhaps he will after you learn how to start your BMW

[Elk]

26 PSI is low, but not low enough to have hurt anything but perhaps your gas mileage.

[Mobster1983]

The Tire Pressure monitoring System (TPMS) takes the current pressure at the time it is reset. If you reset it when there was low air, then it wouldn't show as low.

Run flats use a solid side-wall (usually metal) to hold the weight of the car for a short amount of time when the tire goes flat. However, the weight of the car will cause stress fractures and cracks in the metal. This is why they are only rated for about 50 miles and are not supposed to be repaired. If you get a flat from a nail or something, and drive your car with the run-flats, it is recommended that the tire be replaced instead of repaired. While a repair will still fix the tire and you can drive it with normal tire pressure just fine, if the tire goes flat, the additional stress on the reinforced side-walls can cause the tire to fail, although I believe at that point it will just be like a normal flat. Hopefully it doesn't fail at high speeds.

[utenigma]

26 is low, defiantly not ideal but probably not damaging

If you're really concerned you could get the tires removed from the rims and examine the internal sidewall for damage - also look for rubber powder inside the tire which would indicate the internal walls were shedding rubber.

[tdizzle]

Originally Posted by Elk

26 PSI is low, but not low enough to have hurt anything but perhaps your gas mileage.

+1