I know the sound you are talking about as I had an E53 2004 sport 4.4 and I had the darndest loud tire noise about 20,000 until I put on new rubber. The kicker here is that the 2004 didn't have runflats. I don't think the runflats are your problem, it's the wider tires and suspension or else why would it have been a problem on a 2004?? I think you'll need to get the tire you want and go for it. If you don't want runflats, fine, but they are not the cause of the tire noise.

As an add on ..... I have 20,000 on my 19 inch runflats and no tire noise and I expect another ( hopefully ) 10,000 miles.

Gene, what brand tire are you running?

Craig

Michelin may be better
 

my E70 3.0 d comes with a stock continental 18" tire
I at about 34kilometer now and it is very noisy as well....

I have hear the Michelin has a much lower noise....
However, we I call up the local tire shop and notice it is
out of stock island wide.....
I do mostly freeway driving and do not do much driving on the winding twisty roads in the moutains....
with about another 3 to 4 mm of tread depth before reaching its indicator mark..... I am going to keep driving until the Michelin is avaliable

Michelin!! How many miles you got on the diesel?? Still liking it??

I currently have 19" Bridgestones RFT on my X5. I have 6200mile (10000km) on the vehicle now and I never notice any tire noise.

I carry tire sealant and small compressor in the truck storage. I heard the Slime sealant stuff is pretty good.
I just came back from Disney World, must have put a good 3500+ miles on it and it was smooth and quiet. Probably the most quiet tires I ever had...

Anyways, I will be changing them over next week to 20" 214 Y-spoke w/ Vredestein Sessanta. Everything I heard was great things about these tires in all conditions, dry, wet and even in the snow. Yep, someone took them out during the first snow fall and they said it still gripped well.
Most likely due to the soft compound of the tires but I also heard that it wears pretty good too.

I have 1700 miles and still like it. I've been driving my Lexus more now that the weather has warmed up. I wish I had my Michelin tires back. The dealer swapped my wheels and tires. 3 of my wheels were damaged at delivery and now I have those crappy Bridgestone tires. I will swap them for Michelin's once I wear out the Bridgestone tires. The diesel got smoother and more power around 1500 miles. My mileage isn't great in the cold weather. 17 city and 24 highway @ 80 MPH. When it warms up, my mileage improves. They switched to summer blended diesel the first of April, but I haven't filled up with any yet. The distributor also told me, they don't mix number 1 with number 2 diesel in the winter anymore. It costs too much is what they told me.

Talk to you later,

Craig

Craig, when you say they don't blend 1 and 2 for winter?? I take it they just make winter fuel by using additives?? I think most distributors in Kansas mix 1 and 2 as the additives really don't work well when it gets really cold. I know some stores don't and when it gets really cold customers rush to the distributors that mix to keep from gelling. We have a store on I70 and have one tank which is all 1 so the customer can blend his fuel any percent he wants. Our other stores just blend.
Glad you are enjoying your D. I have had great luck with my 4.8.
Gene

Gene, you're right, they told me, they do it with an additive package. They also have a summer additive package. I go to a group of stations that sell premium diesel fuel. Cetane rating 49-51. BMW won't allow customers to put their own additives in. It says on the gas cap, no additives. I had no troubles with cold weather this winter. My car does stay in the garage at night. No problems to report so far with my diesel. It runs great and gets decent mileage...

Craig

The diesel X5 gets good fuel consumtion.
I actually get about 30 miles per gallon on the freeway...
Lots of low end torque.... Its a turbo inline six, but it pulls like like a V8.....

However, if you are look for a comfortable ride this may not the one... the ride is stiff... yet with excellent control...