So I ordered rotors and pads and both pads and rotors online and both were smaller than what was actually on the car.. I found local shops to also carry the smaller pads/rotors for my model year as well. I did eventually find the needed larger rotors (375mm) at autozone of all places but the pads they paired it with were the same smaller sized ones I was sent by the other company. We apparently have more than one option for brakes on our cars. My issue right now is that i cannot seem to figure out what brake pads I need. The pair I ordered online as well as two sets I bought (or looked at) at local auto shops were the smaller ones that will not fit. I just can't seem to see any way to determine what pads I need verse another with all being listed as compatible to the 2013 GL450.

Has anyone with the larger front rotors dealt with this on a 2013 GL450? What pads did you order? Often when there are changes or options within a model year sites will note it for you, but I am oddly finding very little information about variability for this model year for front pads.

I REALLY wanted to avoid buying pads from the dealer, hopefully, someone here has already dealt with this and can offer some guidance.

looks like you are trying to replace with the aftermarket parts so i am not sure, but i can share my part info for my '14 GL450. i think they are the same.
these part numbers are for OEM stock

rotors 166-421-16-00

pads 008-420-00-20

sensor 164-540-10-17

hope that helps

Are the pads at the dealer that much more expensive? Look up the MB part number on mbparts.mbusa.com and give the MB part number to the counter guy at Napa, Advance Auto or wherever you buy parts.

Put the MB part number into FCP Euro's website.