Good afternoon, going to the Big Island and I REALLY want to do the Summit at Mauna Kea, I keep looking at the different tour companies and average time is 7-8 hours; and as much as I want to go I do not know I want to spend 8 hours doing it.
My question can I drive up to the visitors center at the 9000 + in my "regular" non 4x4 rental.
Thank you for your time.

If you're asking whether you can practically do it, definitely yes. The nasty part of Saddle Road has been bypassed and redone, and there's never been any problem with the rest of the road to the Visitor Center. But if you're asking whether it's allowed under your car rental contract, only they can answer it. Ask them. Again there's no longer any reason to restrict vehicles on Saddle Road but some still might.

fdecarlo:
yes, that's what I want to know if I can do it myself. I think I can settle for staying at the visitor's center. I will check with the rental too.
have a wonderful day.

You can drive up to the VIS in any car. That road is fine. For the summit, you need 4WD. The only rental car company that allows its 4WD to go to the summit is Harpers. They are expensive and difficult to deal with but only rent with them for the day you want to go and use their cars. Be careful as the altitude can impact you and bring very warm clothes as it is cold up there. The biggest issue is the decent on the cindercone road. Make sure you know how to drive a 4WD and keep it engaged in a low gear to prevent burning the brakes. Most of the accidents come from burned out brakes and drivers somewhat incapacitated due to the altitude.

Taitai, thank you for all the information. I will keep at the visitors center.
Thanks again.