Before you leave home make a reservation for a rental car or jeep. There is not enough vehicles to meet the demand at peak season.
We leased a car and had to take a jeep instead. They called it an upgrade but at the price of gas on the islands, we didn't think much of it.
The roads are good and there is no problem driving anywhere that you may want to go.
You cannot go to Hawaii and NOT rent a car. There is so much to see and do.
Hawaii (specially the big island) offers opportunity for a vast amount of eco climates that are not encountered all within one island anywhere else in the world.
You can be atop a mountain (with snow in winter) or, at sea level at a beach, or within a rainforest or even a dessert like atmosphere all within one day - if you drive!
Hawaii is also one of the cheapest places in the US to rent a car but beware; make sure your insurance covers or take out an appropiate policy at time of rental.
Also, be aware that you will need a 4 wheel drive for certain "off road" adventures opposed to a car if you're only planning to drive around cities such as Kona or Hilo.
Whenever possible, go for the 4 wheel, part of the fun of Hawaii is being able to explore and "just pull over"
If you want to drive to the top of Mauna Kea there is literally only 1 rental company to rent from... Harper Car & Truck Rental.
Their trucks are made for the difficult climb and more importantly have the gears for descending the mountain safely.
If you rent from any other company it's prohibited and you could actually end up dead when your brakes fail.
I have to add, it was fun driving this vehicle.
If you're wondering weather you should rent a car for getting around the Big Island or not. Unless you're staying at a resort and don't plan doing much more than staying there, make a reservation for a rental car and you'll be able to get around and see the island.
A few places are only accessible with a 4WD ,and a few places like the sadle road and Manua Kea are restricted by all rental companies except Harpers, but you'll be able to get to most places of interest in a regular car. But if you want to see Waipio valley, Green Sand Beach without getting there on your own feet or opting on catching a ride, you should look into paying the extra bucks and rent a 4WD.
The Big Island has good roads and is nearly impossible to get lost driving because there's only one main road that goes around the island: Route 19.
Renting a car offers you much more freedom to explore the state parks dot along the road, may it be lava tubes, beaches, or scenic vistas.
We rented a car to make our exploration around the island easy and convenient. We stopped along the way to view some beautiful lava tubes flowing with water, the Kaimana Caves, Akaka Falls and then on to Volcanoes National Park.
The route is a short one but a good way to get off the highway and see the beautiful coast line.
They say that little Oahu is just 1/6 to 1/7 the size of the Big Island here. They also say that all the rest of the Hawaiian Islands could fit inside the space taken up by the Big Island here. They aren't kidding. You clearly need wheels if you plan on seeing anything beyond your hotel room on Hawaii. Roads are paved of course and in pretty decent condition, but there will be occasions you need to motor across a single-lane stretch of something which is halfway btwn a road and a newly-dried slab of lava, bumps and ripples and all, and you will then thank your stars that you went ahead and got the Jeep.
Inter-island flights - There are plenty of flights between Oahu and the other islands which run at various times each day. The main airlines are Hawaiian and Aloha with some smaller runs being handled by Island Air and Air Molokai.
Rental Cars : We hired a car for the time we were there which was the best way for us to explore the Island.
Alamo Rent-A-Car . 1-800-GO-ALAMO
Dollar Rent A Car . 1-800-800-3665
On The Big Island, you want to have a rental car with 4WD. There are lots of awesome sights you cannot get to otherwise.
The Ford Explorer was good because we could leave things like the "noodles" we bought to float in the ocean, and our dirty hiking boots and socks in the back - just in case we ever needed them.
This is a must because there are very looonnnnggg stretches of highway before you can get from one place to another. If fact, I don't remember even seeing one bus and maybe a few taxis. Once you land at the Kona airport, there are rent-a-car shuttles that will take you over to the rent-a-car offices.
If you can swing it, renting a convertible is a blast! There are lots of drawbacks though. If you have luggage in the trunk, you won't be able to put the top down unless your luggage is in the back seat. But, the weather is perfect for using a convertible on the Big Island!
We had a rental car that was big enough for all 6 of us to ride in during our 2 week visit. Even though we stayed with family that live there we still had our own car so we could go out & explore on our own.
The best ride I had there? Around town & down the highway on the back of my brother-in-law's Harley. It was beautiful - and there isn't a helmet law so I threw caution to the wind, hopped on the back & had the best ride ever.
If you're going to go see any of the really cool sites, you have to have 4WD. Now, they'll tell you that you're still not supposed to go off of 'marked' roads, but I swear I never saw anyone from the rental companies on those trails checking for their cars.
A short walk from Royal Kona Resort to town was 25mins business. Believe me, you don't want to walk that far under the sun either.
I was so glad to renting a car for the last day so that I could visit the painted church & National Park before catching the flight in the afternoon.
Although there are lots of traffic between Kona town & the airport and driving on the opposite side, it is pretty pleasent to drive on the Big Island.
Unless you plan on just staying at your resort, you will definitely need a car. The island is very large, and all of the points of interest are a good distance away from each other. On the plus side, roads are nicely paved and well marked.
The Big Island is named so for a very good reason - IT'S THE BIGGEST ISLAND, and to see it properly you've gotta' have a car.
This Island bigger than all the other islands combined and has 10 of the 15 climatic zones in the world. This makes for many types of terrain and scenery.
If you plan on checking into a resort and staying there your whole visit - find one closer to home and save a bundle on airfare.