Mauna Kea Saddle Road and Visitors' Center.
 

Four of us will be visiting the Big Island in May and one of my plans is to visit at least the Mauna Kea Visitors' center. We can do this in an Alamo rental car. A Summit tour will cost close to $800 and the Visitors' Center offers an escorted tour on Saturday and Sunday. if you have your own 4WD vehicle. Guests will be allowed into at least one of the observatories. No rental cars, other than Harper's are allowed past the Visitors Center. The cost of a one day rental from Harper's is about $179, less than the cost of one person on a tour. Has anyone driven this as part of the "caravan"? It sounds like a cost effective way of doing it. Thanks for any input.

Dawn CT: Do you mean that the Mauna Kea Visitor's center doesn't allow any rental cars except Harper's to go past the Visitor's Center? Or do you mean that only Harper's allows its rental cars to go past the Mauna Kea visitor's center? Sorry if this is a dumb question!
We also want to visit Mauna Kea and were wondering if any rental car companies allow their 4-wheel-drive cars to go up to Mauna Kea...or anywhere off paved roads.

I am sorry, I wasn't clear. Some rental car companies do not allow cars on the Saddle Rd and the access road to the Visitors' Center at all. Alamo and a few others do. No national rental car companies allow their vehicles beyond the Mauna Kea Visitors Center. Only Harper Rental on the Big Island does. I was advised on another board not to book at the last minute. One particular family did and all they could get was a Ford F350. Big pick up truck. I think this is what we are going to do. Its much more cost effective. We will bring a windbreaker, a sweatshirt and pockets in our jeans and stay warm. If worse comes to worse, we will warm up in the vehicle.

Let us know how this worked out for you!

I just noticed this post, so hopefully, you are still planning things.

My daughter and her boyfriend did the tour three weeks ago. She said it was a really nice tour.

They rented a truck from Harper's for $140. Harper's is the only company that rents 4WD vehicles and allows them on that road, so unless you have your own 4WD, you need to rent from them.

You need to be up at the visitors' center about noon. The tour (which is free) starts with a talk and some videos, then everyone caravans up to the top. My daughter was able to enter two of the observatories and said it was very interesting. Only one person out of the crowd had any problem with athe altitude.

She said they decided to wait up there for sunset, not wanting to spend 20 minutes or so driving back to the visitor center. She says that, in retrospect they would drive back to the visitor center, as the two hours just sitting in the truck till sunset were pretty cold and the altitude did give her a light headache after a while. She said the center has some basic snacks, videos, souvenirs and other things to keep you interested (and warm). You are allowed to drive back up to the top on your own for sunset.

After the sunset, they went back to the visitor center for a stargazing event.

All this was free, so renting a 4WD is a good value overall. She said the main thing is to check the web site. The Saturday tours go once or twice a month, but not necessarily on a set schedule.

Icuy, thank you for your detailed report. I reserved the Harper's vehicle already. I checked the website and it said that they go up every Saturday and Sunday. I am glad you pointed out that they may not go up every weekend. I will be sure to email them before we leave to be sure that they have a tour scheduled. That would be a huge disappointment to rent a vehicle for nothing. Harper's requires a full day deposit and they have a cancellation range to comply with.

You could also drive up to the summit yourself, but you won't be able to enter the observatories. We were lucky that 2 Russian dudes took us up in their 4WD SUV for free. They refused any payment, and were even offended when we tried to offer them something.

The sunset up there was amazing. But make sure you're acclimatize well before going to the summit. Don't drink coffee a few hours before the trip. Take a baby aspirin. Drink lots of water. Coca tea (bought in Peru) always works for us.