My drivers side door jam says 33 psi whereas my tire says 51 psi. Which one do I use when filling up my tire with air?
The tire rating is the maximum the tire can support in any vehicle, and usually isn't used.
Your vehicle doesn't need that maximal pressure. Therefore, fill it to the specs of the vehicle, not to the specs of the tire, assuming the tire is 215/55R17. Filling to maximal pressure the tire can support would make a very uncomfortable ride.
If you have a different width tire than the specs say, then you may want to overinflate a little (thinner than 215mm) or underinflate a little (thicker than 215mm).