[buckybadger]

After reading posts on run flat tires on this forum, I wanted to experiment a bit with different road textures and tire pressure. To my amazement, I found that it may not be a problem with run flat tires but sensitivity to tire pressure. I've noticed that even a decrease in 1-2 PSI below normal recommended tire pressure causes our cars to ride rough, tramline more and increase road feel (BMW normal tire pressure recommended: 32F and 35R).

After keeping my tire pressure at the recommended PSI on both F/R tires, I noticed the ride was pretty good, tramlining was almost negligible and road feel was decent - not too much and not too less. This was true even on rough textures. The car felt really good, handling/feel was great and it drove smoothly on rough texture and I didn't had to hold tight the steering wheel. However, I noticed that after I hit a pothole (purposely) at about 30-35 MPH, my tire pressure on three of the tires reduced by 1-2 PSI below recommended. Then I drove the car and all the bad things that we've talked about here started to come into picture - tramlining, more road feel etc... So I went back after couple of days and hit the same pot hole with the same speed. Wasn't surprised to see a drop of 1 PSI.

Now I've got back to the recommended tire pressure and the car drives really well. I'm pretty happy with the ride quality. I'm starting to believe that as long as I maintain the correct tire pressures, the car will drive the way it is supposed to. I'm also starting to believe that our RFTs are way sensitive to bumps, pot holes as far as tire pressure goes.

So even if you hit a small pothole, there's a very high chance that your tire pressure has reduced by 1-2 PSIs.

Again, this is just from my experience. I'll have to play around a bit more with tire pressure to comfirm for sure and in the meanwhile I wanted to share my thoughts.

Note: All tire pressures were measured when it was cold, first thing early morning.

[jopa489]

TPMS is still no substitute for checking pressures often. But I'd advise against driving your new BMW into potholes repeatedly.

[cjava]

Originally Posted by deznium

After reading posts on run flat tires on this forum, I wanted to experiment a bit with different road textures and tire pressure. To my amazement, I found that it may not be a problem with run flat tires but sensitivity to tire pressure. I've noticed that even a decrease in 1-2 PSI below normal recommended tire pressure causes our cars to ride rough, tramline more and increase road feel (BMW normal tire pressure recommended: 32F and 35R).

After keeping my tire pressure at the recommended PSI on both F/R tires, I noticed the ride was pretty good, tramlining was almost negligible and road feel was decent - not too much and not too less. This was true even on rough textures. The car felt really good, handling/feel was great and it drove smoothly on rough texture and I didn't had to hold tight the steering wheel. However, I noticed that after I hit a pothole (purposely) at about 30-35 MPH, my tire pressure on three of the tires reduced by 1-2 PSI below recommended. Then I drove the car and all the bad things that we've talked about here started to come into picture - tramlining, more road feel etc... So I went back after couple of days and hit the same pot hole with the same speed. Wasn't surprised to see a drop of 1 PSI.

Now I've got back to the recommended tire pressure and the car drives really well. I'm pretty happy with the ride quality. I'm starting to believe that as long as I maintain the correct tire pressures, the car will drive the way it is supposed to. I'm also starting to believe that our RFTs are way sensitive to bumps, pot holes as far as tire pressure goes.

So even if you hit a small pothole, there's a very high chance that your tire pressure has reduced by 1-2 PSIs.

Again, this is just from my experience. I'll have to play around a bit more with tire pressure to comfirm for sure and in the meanwhile I wanted to share my thoughts.

Note: All tire pressures were measured when it was cold, first thing early morning after 12-14 hours of driving.

The RFTs form bubbles very easily. If I were you, I wouldn't purposely hit potholes as an experiment anymore, even if they're small ones.

[Thunder Dump]

Originally Posted by deznium

After reading posts on run flat tires on this forum, I wanted to experiment a bit with different road textures and tire pressure. To my amazement, I found that it may not be a problem with run flat tires but sensitivity to tire pressure. I've noticed that even a decrease in 1-2 PSI below normal recommended tire pressure causes our cars to ride rough, tramline more and increase road feel (BMW normal tire pressure recommended: 32F and 35R).

On my E93 with the 18" RFTs, recommended pressure is 35F/42R. Or so says the manufacturer's sticker inside the driver's door. And if I go over 100mph regularly it is supposed to be 42F/49R.

[BK]

Originally Posted by deznium

Note: All tire pressures were measured when it was cold, first thing early morning after 12-14 hours of driving.

You mean after 12-14 hours of not driving? After 12-14 hours of driving, those tires wouldn't exactly be cold.

[texasbmw325i]

am i really supposed to check the air in my tires even though the tpms light is not on? i never have checked the air in my tires. guess i learned something new

[buckybadger]

Originally Posted by cjava

The RFTs form bubbles very easily. If I were you, I wouldn't purposely hit potholes as an experiment anymore, even if they're small ones.

lol don't worry about it dude...i have tire warranty..

[Perfectus]

Originally Posted by jopa489

TPMS is still no substitute for checking pressures often. But I'd advise against driving your new BMW into potholes repeatedly.

+1

[ELCHIEF]

i am really upset with these stupid run flat tires and with myself. I didnt get the tire warranty when i got my e92. So about 5 months ago my two right tires went on the inside of the tire so i had to buy two new ones. ($450)

now i wake up this morning to go to work and i look at my dash and it shows the sign for low tire pressure. And i'm almost 100% sure i'm going to have to dish out another $225 for a new tire. IDK what to do, i love my car but dam i cant keep dishing out $500+ a year for these stupid run flat tires that dont last. help me out guys, no stupid comments please.

[rc'Z]

Originally Posted by Thunder Dump

On my E93 with the 18" RFTs, recommended pressure is 35F/42R. Or so says the manufacturer's sticker inside the driver's door. And if I go over 100mph regularly it is supposed to be 42F/49R.

That would be with four people and luggage.

[madmanhiker]

I too am very dissatisfied with my RFT's (but there are ton's of threads on here that speak to that) I will say one this, aside from the typical "complaint's" with RFT's... I'll tell you that I have been driving around with a nail in my RR since last year October. (yea) Occasionally, I'll get a TPMS light, and I'll add some air and be on my way. Another note, I work out of my home and my daily commute MAY include 0 miles... lol. When I do drive, it's locally here in town and it's spirited driving. I will be replacing the tires here soon, most likely with a purchase of some VB3's from JLEVISW... but.. the RFT's do has their advantages. My next tires will not be RFT's however, and I'll have to locate a spare as well for the nail that does the tire in..........