Brought my 2018 CR-V EX-L to dealer for oil change with 30% life left on the MM (no codes showing). With 17k miles, dealer recommended rear differential fluid change. Dealer stated that Honda recommends change at 15k miles and after that I would be good for 30k miles. I'm assuming that the replacement fluid is the same as what is used in the new vehicle. Service rep claims there is a break in period for the differential and that's why the difference in mileage. Could not find any info from Honda on this. Dealer also claimed that there was A-1-6 code even thought it was not displayed. $95 for fluid change, which I declined and dealer never mentioned anything about it voiding the warranty, but I'm considering having it done but just feel this is unnecessary maintenance. I've been driving for over 55 years and probably had 20 or so new cars and never heard something like this before. Am I missing something or does this have something to do with the AWD system. I understand about gears meshing and wearing in, and maybe minute metal particles in the oil, but I think that reasoning would apply to all cars. Thanks for all opinions and experiences.