Going 3 days in Oahu, staying in Waikiki (don't ask why - but at least in Halekulani). 4 adults. The only place I can think of that needs a car is Pearl Habor (parents in laws wanna go). So, should I rent a car, or should I cab to Pearl Habor and back that one day? Would rather no join a tour, so any other recommendation?

We hate taking cabs. A normal car will cost you about $30/day or less. If you're going on a weekend, you can get a free day off with a Hertz coupon as well.

How are you getting to the hotel?

I say get one at least the day you go to Pearl Harbor and to drive around and see the north shore. Being stuck in Waikiki sucks.

I usually rent a car, but think Oahu is the one island where it's really easy not to. Check out http://www.thebus.org/

Although I like Waikiki & can find plenty of things to do there, I think it really helps to have a car. As Tummy mentioned, the circle drive around the island to the North Shore & back via is really fun & beautiful. Be sure to check out the Shrimp Trucks & cruise through the neighborhood at Lanikai to see all the 6 Mil & up beachfront shacks - some really are nice, but we went to a few open houses in January & for 6 mil you got a house I wouldn't even consider living in - nice view though! Also fun to drive around Diamondhead & Kahala. The best restaurants (other than La Mer at your hotel) aren't walking distance (then can easily be reached by cab, though) - Alan Wong's, Chef Mavro's, Diamond Head Grill. We always get complimentary use of the limo at the Hyatt Regency (although the tip is usually more than a cab fare ), does the Halekulani have the same service? If yes, reserve well in advance as they get booked up quickly & often don't drive after a certain hour. Have fun in Waikiki & on Oahu - yes, some of it is tacky, but it can be a lot of fun & the rest of the island is truly spectacular for the most part.

Many hotels charge a parking fee... and then the gas prices... but then again, I have always rented a car (I just looked fort he cheapest one I could find..)

Why rent a car, pay for parking, if you'll only use it one day?

Halekulani is next to the Outrigger Reef & Sheraton Waikiki, both of which have rental car counters within.

While I agree the drive around the island is fun, I wouldn't pay for keeping a car in the garage ($15 / day at the Halekulani if I remember correctly) just to use it for a single day.

Pay a dollar or two more and just rent for the day you need it.

Short answer, no you don't need a car IMHO.

Aloha

Lihu'e 1k

i agree with lihue 1k. get a car for the day if you want it, if you are happy staying centered in waikiki, on foot, and/or with a few cab rides. a car in waikiki isn't fun and isn't essential. sometimes i just like to free myself from a car. also really turns up the exercise, walking from one end to the other.

Waikiki is probably the one place in Hawaii where you don't really need a car, except for the day trips mentioned above. The plan others mentioned above of renting a car for just the day at Waikiki is a good one.

Even if the money spent is close (rent from airport, park at hotel vs. cab, rent, cab), having the car for just when you need it is a little less hassle.