Springfield IL is the final destination. I would want to travel international see if I can use my points to get a business/first class fare, but need to accumulate enough points. I just signed up for National emerald club, maybe I'll a better return than Hertz Gold. I am not able to find a conversion from National to AA though.

Just look the hotel loyalty web sites to determine the earnings, including for status
Then crunch some numbers in a spreadsheet

The grass in not always greener on the other side.
All in the AAdvantage web site--->https://www.aa.com/i18n/aadvantage-p...tners/cars.jsp
Rental car partners can earn AA miles at different rates.
And look at the car rental loyalty web sites.

Not all rental car loyalty programs have an option to convert their loyalty points to other programs. In most cases you would simply earn airline miles when selecting that option as your earning preference for a given rental. So if you chose AAdvantage as your earning preference on a rental and earned say 200 AAdvantage miles, those miles would just show up in your AAdvantage account a few days or so after the rental ended - no need to do any transferring.

The everyday airline mileage earnings from rental cars won't be anything to get too excited about but every little bit helps. The thing to keep an eye out for is periodic special promotions with extra bonus miles from rental car partners.

Even on the other side of the Emerald Aisle?