Reverse-in or forward-in: which needs less room?

There is no universal winner. The useful comparison is geometric: which maneuver gives your vehicle more clearance at the opposite driveway edge and garage corner?

Forward-in

The front of the vehicle leads the turn. It is easy to judge visually, but the rear body can swing differently from the front wheel path and the vehicle may need more apron before it is aligned with the opening.

Reverse-in

The rear enters first while the front remains in the apron. This can make some tight side-entry layouts easier, and it can make the eventual exit simpler, but it requires the driver to position the vehicle well before backing.

Compare comfort, not only possibility

If one mode barely clears and the other has a meaningful margin, use the higher-margin plan. Daily parking should not require centimeter-perfect steering.