The best way to determine which one you have is by having someone decode your vehicle identification number. Every car has a VIN, which you can find by climbing up on your hood and reading the little metal plate that sits where the dashboard meets the windshield. Or, if you want to save yourself the trouble, just look for it on your vehicle registration.
It has all kinds of information coded in it. It’ll tell you the year, the model, the engine size, the transmission, the drive ratio of the differential, whether you got the salesman to throw in free floor mats … it’s all there, encoded in the VIN.