Originally Posted by JohnOfTheJungle

If your weight is more distributed on the rails that run lengthwise (not the crossbars) then it should handle much more. People sleep in rooftop tents up there and that’s gotta be several hundred pounds.

Originally Posted by dadrunner

I think this is the key difference.

Sleeping in a tent while vehicle is parked would be much different than loading several hundred pounds on top, then barreling down the highway at 65MPH and hitting a pothole, or going into a sharp turn.

So I would imagine the roof can handle quite a bit while static, but once moving, things can get dicey, and affect handling and safety.

I think the limit given by Toyota is calculated to leave a large safety margin for emergency handling etc.

Originally Posted by BeeRunner

So i've read a lot of conflicting information about what the weight limit on the roof of the 4Runner is as i've wanted to add a rooftop tent and the only limit I can find in regards to weight in the 4RNR manual says 120 lbs max. I decided instead of trying to figure it out in the forums and second guessing myself i'd just contact Toyota. The following is my email and their response:

My Email:
08/04/2017 09:39 AM
I'm buying a 4RNR that is expected to arrive in two weeks from today. I've seen several with rooftop tents added on the rails on the roof of the 4Runner. Reading through the manual it says not to exceed 120lb in the rooftop luggage compartment. That is the only reference to weight for the rooftop in the entire manual; however, people exceed this weight all the time with their tent setups, especially while they have people sleeping in the tent. Is Toyota saying that 120lbs is all that the roof can carry, OR are they saying that's all Toyotas crossrails will carry, OR i've heard the theory that that is dynamic load limit for when the vehicle is moving but that when its static (stationary) the roof can hold much more. But I have no actual definitive answer and I can't find anything from Toyota that states specially how much the roof the can hold using adequate crossbars to span Toyotas factory installed roofrails.

Toyotas Response:
Dear Mr. XXXXXXXXXX,

Thank you for contacting Toyota Motor Sales, U.S.A., Inc.

We are very sorry; however, due to a high volume of email contacts, we were unable to respond to your inquiry in a timely manner. We sincerely apologize for any delay and we appreciate your understanding, as it is never our intention to keep a customer waiting.

We apologize as we do not recommend or assist with modifying our vehicles from the original factory specifications. The maximum roof capacity listed is 120 Lbs.

Toyota's warranty covers repairs and adjustments needed to correct defects in materials or workmanship of any part supplied by Toyota.

Modifications to your vehicle could affect the performance, safety or durability, and may violate government regulations. Non-Toyota parts, or any damage or failures resulting from their use, are not covered by any Toyota warranty.

Your email has been documented at our National Headquarters. If we can be of further assistance, please feel free to contact us.

Sincerely,

Teayra R.
Toyota Customer Experience Center

Conclusion:
Even though people add much more weight than 120lbs in their rooftop setups, Toyota is only willing to claim a 120lb limit on their roof. If you add the extra weight you do so at your own risk and you won't be able to count on Toyota for any warranty work.

Originally Posted by BetterontheMtn

this will be the exact same response you get from nearly all brands. No matter the age of the vehicle, the line always be the same.

Originally Posted by motoraway

Traveling this summer with 2 kids, 2 dogs, 2 adults is going to be a challenge. Was searching this site for roof weight limit and decided to stick to using our Yakima rocket box (40 lbs) for tent, sleeping bags, clothes, etc. and going to get a hitch cargo carrier for the cooler and kitchen camping box. Now, hopefully, we keep it below the GVWR!