You'd probably be more limited by your tires and how steep the incline begins. Have you measured the incline you've been driving on? Plenty of phone apps that contain inclinometers... You could probably find a cheap inclinometer as well.
Once you know the incline degrees, you could always compare it to the many, many examples out there for other 4x4s, suv's, etc that are posted both stock and modified on other sites.
Good luck.
Oh, come back and update if and when you find out.
I spent a lot of money on booze, birds and fast cars. The rest I just squandered. - George Best