4WD cars for Mauna Kea

[TomK]

PS. Some here have pointed out that "normal" cars can make it to the summit region of Mauna Kea and make it back down again. Of course, they can. However:

1) Whether you agree or disagree with them, current regulations mean you are not allowed to drive a non-4WD vehicle on the dirt road above the VIS;

2) Even if you rent a 4WD vehicle and take it to the summit area, you need to make sure the rental company allows you to take their vehicle beyond the VIS. If you break down or have an accident up there, you'll be paying the consequences.

This is why I asked about rental companies that allow their vehicles to be driven on Mauna Kea.

[achutch3]

I go up once in a while and was just up there a few weeks ago.

I drive a 4WD Tacoma and from my perspective the need for the 4WD is for coming down the mountain.  I think most normal 2WD vehicles would be very capable of going up the mountain but it is coming down where the concern is.  

Using 4WD low I can descend the whole mountain without touching my brakes.  Actually, the last 2 times I was at the mountain the rangers have you stop at the road block and use a temperature gun to check the temperature of your brakes.  Ranger told me they were looking for a temperature of 200 or below.  If you are above the 200 I assume you will need to wait until the temp comes down to proceed the rest of the way down the mountain for fear of brake failure.

In all honesty I still keep my truck in 4WD all the rest of the way down the access road because it is still very steep from the ranger's station down to the highway and the possibility of overheating your brakes is still very high.  I am pretty sure overheated brakes is what caused the crash and fatalities below the ranger station previously.

As far as Waipio goes I don't think its as much about brake fade as it is just overall safety since the road is so short and overheating the brakes would not be as likely as descending Mauna Kea.

The ascent up the hill out of Waipio may be a problem for normal passenger vehicles loaded with 4-5 passengers and gear.  Also, once at the bottom of the road if you are trying to get to the beach you will need some serious clearance due to the huge ruts and "ponds" you will need to go through to get to the beach.

[AaronM]

Very well said!

[TomK]

achuch3 - excellent post, thank you! As you point out, 4WD is needed when driving down the mountain on steep slopes, it's not required for driving a car to the summit region. As for using 4WD on paved surfaces, I think I'll leave that to others more expert in the field. As observatory staff, we are not allowed to use 4WD on the paved road (unless they are icy or snow-covered) and think it's due to the hubs being locked and the turning ability being compromised. However, this comes from decades ago when we drove Broncos to the summit and had to actually get out of the vehicle and lock/unlock the hubs when switching between 2WD and 4WD. I don't know if locked hubs are still an issue with modern 4WD cars.

When driving down below the VIS, I use the brake-stabbing technique dobanian mentioned earlier in the thread, but that requires you to have used 4WD low on the dirt road above the VIS to avoid having hot brakes beforehand.

[Durian Fiend]

PS. Some here have pointed out that "normal" cars can make it to the summit region of Mauna Kea and make it back down again. Of course, they can. However:

1) Whether you agree or disagree with them, current regulations mean you are not allowed to drive a non-4WD vehicle on the dirt road above the VIS;

2) Even if you rent a 4WD vehicle and take it to the summit area, you need to make sure the rental company allows you to take their vehicle beyond the VIS. If you break down or have an accident up there, you'll be paying the consequences.

This is why I asked about rental companies that allow their vehicles to be driven on Mauna Kea.

So was the search for a rental 4WD successful?

[TomK]

Yes, I now know of two rental companies that will let you drive their vehicles above the VIS.