i've had a 2013 rdx and now drive a 2017 rdx.
need more details:
1. what is your percentage of city vs hwy driving?
2. what gas are you using? rdx recommends premium 91
3. whats your driving like? i.e. jack rabbit starts etc (i know its tempting with that gorgeous 3.5L V6)
4. what is the current mileage on your RDX?
check out the facebook rdx site and post there as well:
https://www.facebook.com/groups/AcuraRDX/