If you look closely at the lowest part of the oil pan, you will notice that the drain plug hole is slightly above it. Regardless, it’s easier for the DIYer to raise just the front of the vehicle, and nobody raises the back of the vehicle because it’s a pointless waste of time. Sure, the people who do oil changes on a lift raise both front and back of the vehicle, as most lifts aren’t capable of lifting the front independently of the rear. Bottom line is that you can’t fight gravity.The J35 oil pan is already designed with a slope toward the drain plug. The vehicle was designed to change the oil when level. Putting it on ramps won't hurt a thing, but it also wont make any difference. Changing the oil when the vehicle is level will not "hinder" the oil change in any way.