I have a 2006 530i and the recommended tire pressure differs depending on speed and load. For me the speed and load differs greatly, and changing tire pressures constantly would be a pain the rear end. Is there any drawbacks to keeping the pressure set at the max which is 36 front and 44 rear. It roughens the ride, but improves the fuel economy, at least I have been told.

Is this true?

Are there any handling drawbacks?

What exactly does the increased pressure do to accomodate higher speeds?

Someone know these answers...common!

The owner's manual has everything you need to know:

Attachment 11051
Attachment 11052
Attachment 11053
Attachment 11054

Yes, max pressures ruoghens the ride, but that's about the only drawback. In slow speeds the tire is of course much less flexible but if the suspension is in order this should not be a problem.

And note, it DOESN'T increase tire wear in the centers. This is a old beliving from the '70's when the tires where what they where.

The tyre is under much more pressure whilest driving fast or rough. If the tire pressure is not on max, the tire can "bend under" and even get loose from the rim.

Here's an interesting read from Tire Rack. Anc, do a search on "tire wear." The various tire-wear guides continue to mention center wear from over inflation. However, it also may be true that such concerns are not as great as they used to be.

Here's an interesting read from Tire Rack. Anc, do a search on "tire wear." The various tire-wear guides continue to mention center wear from over inflation. However, it also may be true that such concerns are not as great as they used to be.
[/quote]

Good reads, donv. Other than comfort, higher (within specs of course) seemed to be better from the reading I did. Any reference to center wear seemed to point to "over" inflation, which appears most of us would not do. Did you notice how well the Tire Rack article on tire inflation versus speed tracked with the BMW manual recommendations Das posted. Apparently alot more research in Europe due to the increased speeds that can be driven regularly in there (well at least Germany). I have started going to just under the max recommended pressures, although I run a light load generally. That is what I have done on other car/tire combos with great success, at least on the tire wear side.

Here's an interesting read from Tire Rack. Anc, do a search on "tire wear." The various tire-wear guides continue to mention center wear from over inflation. However, it also may be true that such concerns are not as great as they used to be.
[/quote]

Good reads, donv. Other than comfort, higher (within specs of course) seemed to be better from the reading I did. Any reference to center wear seemed to point to "over" inflation, which appears most of us would not do. Did you notice how well the Tire Rack article on tire inflation versus speed tracked with the BMW manual recommendations Das posted. Apparently alot more research in Europe due to the increased speeds that can be driven regularly in there (well at least Germany). I have started going to just under the max recommended pressures, although I run a light load generally. That is what I have done on other car/tire combos with great success, at least on the tire wear side.
[/quote]Yes, I did note the correspondence you mention. And, higher definitely is better given very fast driving. The pressures that BMW give exactly mirror the idea from the article that they are aimed at European fast-lane driving. And, I too am not near the maximums for in town driving. But, for the road, I will bring them up some after reading the article. As mentioned, I am at 34 [R] and 32 (F). What are you running exactly? I once put my pressures up to the BMW recommendation and found the ride uncomfortable in general.

Anyone in Germany know the conversion between PSI and bars? I live in Germany and the local Esso station has a digital air pressure filling station that is in bars.

Since you're on the internet, wouldn't it be quicker to just search for it? ;)

1 psi = 0.06895 bar
1 bar = 14.50326 psi

I run 36/44 all the time and am happy with that pressure.

I'm running the 29/35 pressures in my 2006 530i Sport (245/40 18") and have been for a few months. I noticed an immediate 2mpg decrease in fuel efficiency, but the car seems smoother over bumps.

Here's an interesting read from Tire Rack. Anc, do a search on "tire wear." The various tire-wear guides continue to mention center wear from over inflation. However, it also may be true that such concerns are not as great as they used to be.
[/quote]

Good reads, donv. Other than comfort, higher (within specs of course) seemed to be better from the reading I did. Any reference to center wear seemed to point to "over" inflation, which appears most of us would not do. Did you notice how well the Tire Rack article on tire inflation versus speed tracked with the BMW manual recommendations Das posted. Apparently alot more research in Europe due to the increased speeds that can be driven regularly in there (well at least Germany). I have started going to just under the max recommended pressures, although I run a light load generally. That is what I have done on other car/tire combos with great success, at least on the tire wear side.
[/quote]Yes, I did note the correspondence you mention. And, higher definitely is better given very fast driving. The pressures that BMW give exactly mirror the idea from the article that they are aimed at European fast-lane driving. And, I too am not near the maximums for in town driving. But, for the road, I will bring them up some after reading the article. As mentioned, I am at 34 [R] and 32 (F). What are you running exactly? I once put my pressures up to the BMW recommendation and found the ride uncomfortable in general.
[/quote]
My manual recommends 39R and 33F for max load/speed. I started at 32R/29F (low end spec), Ran that way for about 2000 miles. Went to 35R/31F, could not tell difference in ride as much as cornering (better turn in). Stayed that way for some time and only recently have gone to 37R/33F. Not enough road surfaces yet to tell much about comfort (need those speed bumps, don't you know), but normal drive ok so far. With sport pkg has always felt stiff but complient so no disappointment at all so far. For the Cabrio version on same tire/wheel they increase the min and max pressure recommendations by 7R/6F PSI so load is significant factor.

Here's an interesting read from Tire Rack. Anc, do a search on "tire wear." The various tire-wear guides continue to mention center wear from over inflation. However, it also may be true that such concerns are not as great as they used to be.
[/quote]

Good reads, donv. Other than comfort, higher (within specs of course) seemed to be better from the reading I did. Any reference to center wear seemed to point to "over" inflation, which appears most of us would not do. Did you notice how well the Tire Rack article on tire inflation versus speed tracked with the BMW manual recommendations Das posted. Apparently alot more research in Europe due to the increased speeds that can be driven regularly in there (well at least Germany). I have started going to just under the max recommended pressures, although I run a light load generally. That is what I have done on other car/tire combos with great success, at least on the tire wear side.
[/quote]Yes, I did note the correspondence you mention. And, higher definitely is better given very fast driving. The pressures that BMW give exactly mirror the idea from the article that they are aimed at European fast-lane driving. And, I too am not near the maximums for in town driving. But, for the road, I will bring them up some after reading the article. As mentioned, I am at 34 [R] and 32 (F). What are you running exactly? I once put my pressures up to the BMW recommendation and found the ride uncomfortable in general.
[/quote]
My manual recommends 39R and 33F for max load/speed. I started at 32R/29F (low end spec), Ran that way for about 2000 miles. Went to 35R/31F, could not tell difference in ride as much as cornering (better turn in). Stayed that way for some time and only recently have gone to 37R/33F. Not enough road surfaces yet to tell much about comfort (need those speed bumps, don't you know), but normal drive ok so far. With sport pkg has always felt stiff but complient so no disappointment at all so far. For the Cabrio version on same tire/wheel they increase the min and max pressure recommendations by 7R/6F PSI so load is significant factor.
[/quote]
Thanks for the info cobradav. I may experiment a tad more.

I run 36/44 and the only real difference I feel is a harder ride but the handling is great, corners real nice and coming into highway curves at a decent rate of speed you feel comfort as opposed to feeling the G forces...... I am happy with the 36/44.......buts thats me. :rolleyes:

On my 2005 530i (non-SP), run 30 front & 35 rear with 2 persons and no luggage. Occasionally, have to drive on roads that are pretty bad (potholes, etc.) and hate a bone-jarring ride.

No doubt, higher tire pressure would improve handling but the loss in ride comfort is too high a price to pay.

Have never understood BMW's unequal (front-back) tire pressure recommendations, since there is a 50-50 weight distribution. Have been told that it has to do with handling.

Martin

I had my car in for some work - including false RFT warnings - as part of that they must have reset all of my trye pressures.

I was running with 36F / 44R, but when it came back it had 32F / 36R.

These seem low loo me but I must admit the ride is a little better.

Same here.
cheers
vern

owner's manual, then set the tire pressure monitoring thing, should be good