I think the roof rack has a 75lb weight limit, probably more against increasing the potential for rollover vs mechanical strength.
The 2005 RX330 Manual states that the roof rack can support 75kg (165 Lbs)... Which is good...
My Thule Atlantis 1600 fits perfectly and the box itself is about 35-40lbs, which leaves about 120lbs of cargo possible.
My recommendation isn't to max out the weight you put in the top of the car, or you may be looking out the drivers side window and seeing the ground close-up. Making the vehicle too top heavy is never a good idea.
I use my cargo carrier for trips. Usually baby stuff (strollers, chairs, shelters, etc. go up there.). Heavy suitcases and other items definitely stay in the cargo area inside the SUV. I want as much weight as possible low in the vehicle if I'm loading up the thule box on top.
Think of a rack top cargo box as a place to put bulky items.. not heavy ones.. and you'll be ok.
If you want another heavy storage area, get one of the Thule trailer hitch mounted boxes.
Yes, but all means, put the HEAVY load out beyond, behind, the rear axle, bumper even, that will only result, WORSEN, the potential for loss of directional control on a vehicle already highly subject to same, FWD, F/AWD understearing/plowing.
They work extremely well on these light trucks. (especially since the trailer hitch on these things really can't tow much.)
My opinion, worth 2 cents.
-Chris330
I'll give you a penny for the good advice, heavy low loading with light Thule roof loading, but with-hold the second penny for the POOR rear loading advice.
Oh sure... you and your wife probably only weight 250lbs together... me and 'shewhomustbeobeyed' tip the scales together at 600, so we're just equalizing the load...
:chairshot: