I have a 04 e500. At 45k miles I have used up two sets of rear brake pads. I have replaced the front only once. The rear rotors has grooves cut into them also. I took in for service and was told everything is operating properly. Has anyone else experienced this?

A lot depends on how you drive.. But getting 20-25k miles seems fine, on my old ML I would be lucky to get 10-15k miles on rotors. The cars are heavy and the pads and rotros are "soft" so you get good performance stoping. I noticed on the newer 07's they use new rotors that seem to be harder and harder pads since I dont see the brake dust anymore and by looking at them they seem to have a higher metallic content in them more inline with sports cars. You might want to ask if you can have the newer rotors and pads from an 07+ put in, or you may want to check out brembro which would would end up being cheaper.

Your experience seems normal. I just replaced all 4 rotors and pads at 45k, all 4 rotors were deeply grooved. I think Ive replaced the front pads once and the rears twice. The rears weren't quite ready to be replaced but I did anyways.

I used Akebono ceramic pads and would highly recommend them! No sqeal, no dust, they are great.

Thanks for the pad recommendation.

I am still looking for Akebono ceramic pads for my 2007 E320. Anyone with a source information please?