I got my car with 30k miles and have only done 17k miles. They put new tires on when I got it and now they are telling me the rear tires are trash... is that normal? 17k miles only? The tires are the dunlop oem sizes and I drive relatively calm. Is that normal?

 

Depends on the tire, the compound used and of course alignment and driving style. There are softer tires that will wear much more rapidly, but give much better grip, then there are harder tires that give much better life but sacrifice grip to do it. Then there's the negative camber in the rear tat every BMW has, regardless if the car is in perfect alignment negative rear camber is spec'ed.

 

and depend on how much camper / tow and alighment thing
good tires and good alighment and good driving I mean driving smooth in corners and slow will keep your tires in good condition for atleast 3 years

 

OP said OEM size dunlops, I read that as the standard run-flats. I would say 17k miles on the rears is not bad given the camber... On my '08 550 I got just shy of 20k on the OEM Continentals but I was not pushing the car. I recall some getting 15k or less on the rear OEM tires.

 

Had my OEM Continentals replaced just before 20k (hit 20k in October) with Bridgestone Potenzas. Longer life for sure but (maybe I'm overly-perceptive) I can really feel the difference. Next time I'll probably go with Continentals despite the low wear rating. The car just handles so much better with them.

 

My 2008 550i sport got 17K only from the OEM conti's. Replaced with Michelin a/s plus and have 31K on them and the rear wear bars are flat so they need replacing. The fronts have another 15K left easy. I drive 70 miles a day on curvy two lanes and enjoy the car when possible. Air pressure is huge and I have reduced my negative camber on the rear from -2 degrees to -1 degrees . You get what you pay for.

 

It's all dependent upon the tire treadwear rating and your alignment. The lower the treadwear rating, the quicker they will wear out, but in most cases will provide better dry traction. I don't think it has anything to do with how much you spent on a set of tires as Pilot a/s plus has a higher treadwear rating which means longer life. On the e60, the rear axle can be adjusted to reduce the negative camber that set by the factory.