Tire pressure...what are you running?
06-04-2004, 03:18 AM
#11
Contributors
Join Date: Apr 2004
Location: Suwanee, Ga - USA
Posts: 510
Likes: 0
Received 0 Likes
on
0 Posts
I'll need to remember that when I take the car in for tire rotation, etc. I bought the little BMW Roundel valve stem caps, so I don't want to lose them.
Of course, I did notice that my 5 year old daughter had taken two of them for her bicycle. We had a little discussion about Daddy's car, and military school. The caps are back on the car.
James
Of course, I did notice that my 5 year old daughter had taken two of them for her bicycle. We had a little discussion about Daddy's car, and military school. The caps are back on the car.
James
06-04-2004, 04:10 AM
#12
Senior Members
Join Date: Nov 2003
Location: Norway
Posts: 723
Likes: 0
Received 0 Likes
on
0 Posts
RPA does not use radio transmitters. You could fit any tyre, anytime, and RPA would still be in effect.
It utilises the ABS sensors to measure the rotation of the wheels.
So having to use plastic valve caps is simply a piece of bovine scatology from you dealer.
-paasan
It utilises the ABS sensors to measure the rotation of the wheels.
So having to use plastic valve caps is simply a piece of bovine scatology from you dealer.
-paasan
06-04-2004, 05:52 AM
#13
Members
Senior Members
I'm running 38 psi front and 42 psi rear. Pretty high and at the upper-end of the limits printed on the door jam. My salesman who's also an enthusiast with a modded E39 M5 recommended staying up there. He said the higher pressure will help avoid bent rims due to pot holes. I didn't notice any difference in the ride either. Infact when I took delivery of the car they had pumped 42 psi in the front and 45 psi in the rear which I thought was insane..
06-04-2004, 05:55 AM
#14
Super Moderator
Join Date: Mar 2004
Location: Pittsburgh, PA USA
Posts: 17,310
Likes: 0
Received 2 Likes
on
2 Posts
My Ride: G30 M550i
Model Year: 2018
Mark, thanks for the info. I may boost the pressure in mine a bit too.
If you don't find any problems with the ride/handling, the only thing you should be watching out for is premature wear on the center of the tires.
Since these tires don't last long to begin with, I'd hate to see anyone blow through a set early due to overinflation.
If you don't find any problems with the ride/handling, the only thing you should be watching out for is premature wear on the center of the tires.
Since these tires don't last long to begin with, I'd hate to see anyone blow through a set early due to overinflation.
06-04-2004, 06:16 AM
#16
Super Moderator
Join Date: Mar 2004
Location: Pittsburgh, PA USA
Posts: 17,310
Likes: 0
Received 2 Likes
on
2 Posts
My Ride: G30 M550i
Model Year: 2018
I hope so too but I wouldn't use the max psi rating on the tire as a barometer against uneven tire wear.
You probably already know this but I'll say it anyway:
The weight of the car, the suspension geometry, etc., all contribute to how the tires will wear. Usually, the recommended pressures of the car manufacturer will try to account for all these things.
The max pressure stamped on a tire is simply to protect you from tire failure. The tire manufacturer doesn't know what car is above it -- it just knows it's ability to dissipate heat at speeds, etc.
You can easily cause uneven tire wear with tires that are not properly inflated but still below the maximum pressure the tire allows based on all these factors merging together.
You probably already know this but I'll say it anyway:
The weight of the car, the suspension geometry, etc., all contribute to how the tires will wear. Usually, the recommended pressures of the car manufacturer will try to account for all these things.
The max pressure stamped on a tire is simply to protect you from tire failure. The tire manufacturer doesn't know what car is above it -- it just knows it's ability to dissipate heat at speeds, etc.
You can easily cause uneven tire wear with tires that are not properly inflated but still below the maximum pressure the tire allows based on all these factors merging together.
06-04-2004, 06:56 AM
#17
Contributors
Join Date: May 2004
Location: Dallas, TX USA
Posts: 4,144
Likes: 0
Received 0 Likes
on
0 Posts
To reinforce what Rudy said -- I have always benefited from running the door-post pressures. I have yet to have uneven wear on a tire to the extent that one needed to be replaced prematurely. The set that my son is now finishing up on the 540 is very evenly worn and they are just about spent.
Now Lomag's sales person made a pretty good point about pot hole protection, not a big problem in Dallas, though. In a pot hole environment I may be weighing the cost of wheel straightening against premature tire wear down the center (and writing letters to the editor about street maintenance).
Now Lomag's sales person made a pretty good point about pot hole protection, not a big problem in Dallas, though. In a pot hole environment I may be weighing the cost of wheel straightening against premature tire wear down the center (and writing letters to the editor about street maintenance).
06-04-2004, 12:45 PM
#19
Members
Join Date: Jan 2004
Location: Romania
Posts: 145
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by paasan' date='Jun 3 2004, 12:58 PM
And guess what.. just now we got one more warning about a "Tyre puncture" from the RPA. Seems none of the tyres differentiate in pressure from what they are supposed to be at - i'll have one more check now whenever the tyres cool down.
It's probably our 6th or 7th incorrect warning in just 2000-3000km - wonder how that'll be this summer on our 8000km trip
Probably slightly confusing when traveling along the Autoroute and Autobahn. These errors turns the RPA system completely useless - while driving it's impossible to tell if there is an actual puncture rather than a software error.
The dealer has also tried to correct the error twice through software updates - but the error seems more like a failure in the fundamentals of the RPA monitoring algorithm rather than a HW malfunction. Anyone else experiencing frequent RPA warnings?
-paasan
It's probably our 6th or 7th incorrect warning in just 2000-3000km - wonder how that'll be this summer on our 8000km trip
Probably slightly confusing when traveling along the Autoroute and Autobahn. These errors turns the RPA system completely useless - while driving it's impossible to tell if there is an actual puncture rather than a software error. The dealer has also tried to correct the error twice through software updates - but the error seems more like a failure in the fundamentals of the RPA monitoring algorithm rather than a HW malfunction. Anyone else experiencing frequent RPA warnings?
-paasan
When I have a RPA warning i have to open the trunk, get the device and check each tire cause they all look the same since they are runflats.
I dont know why but i feel it should be vice-versa.
And to answer the topic i use about 10% higher than the pressure recomanded by BMW and about 10% less than the dealer inflated them on several ocasions.
Front:
BMW 2,2bar; Me 2,4bar; Dealer: 2,7bar.
Rear:
BMW 2,5bar; Me 2,8bar; Dealer: 3,0bar.
I drive mostly alone in the car with no luggage.
06-04-2004, 01:44 PM
#20
Senior Members
Join Date: Nov 2003
Location: Norway
Posts: 723
Likes: 0
Received 0 Likes
on
0 Posts
The current monitoring system on the 5series would not be able to report a puncture on all tyres.
Some time ago I posted a link to a thurough test of all of BMW's tyre pressure monitoring systems.. let me see... this test conducted by the National Highway Traffic Saftety Administration. It gives a pretty good picture of how the RPA (reifen panne anziege) system of the E60 works, aswell as other systems developed by BMW.
The link is not to the original PDF document, but to Google's cache.
-paasan
Some time ago I posted a link to a thurough test of all of BMW's tyre pressure monitoring systems.. let me see... this test conducted by the National Highway Traffic Saftety Administration. It gives a pretty good picture of how the RPA (reifen panne anziege) system of the E60 works, aswell as other systems developed by BMW.
The link is not to the original PDF document, but to Google's cache.
-paasan