If you want to go to beaches with difficult access, you will need a Jeep or at least a 4x4. With a small car you can get everywhere, some roads you will have to go a little slower, but there is not much traffic and life on the island is quiet as well.
If you plan to do a lot of exploring or off-road driving, a 4x4 vehicle can provide you with more versatility and flexibility. It's important to note that 4x4 vehicles may be more expensive to rent than regular cars, and they also consume more fuel. Also, find out where to rent a car in St. John’s.
