Janelle: WELCOME to iRV2.com

We are glad you joined and posted. The info given by RV Dude is correct, and the answer is going to be determined by which chassis you have. Assuming you have a 22,000 GVWR chassis, either Ford or Workhorse, the MAX total combined weight for both loaded coach and loaded MDX cannot exceed 26,000 pounds. Most of us using 22,000 chassis find a 3,200 pound toad such as the Honda CR-V or Saturn Vue to be about all we can tow. Please don't forget that WHATEVER you decide to tow, you WILL need aux. brakes for the toad.
Again, WELCOME! ED