700 lbs on Hitch?

I am looking into buying another minivan and want to install 3 cargo boxes on the hitch (total of 40 cu.ft.) and a 4-bike rack on top. I estimate total weight to be 620-650 lbs, so let's say 700 lbs.

Is this possible? Would the problem be with the hitch structure itself? Or the attachment points hitch-to-chassis? Or chassis strength itself?

Since this will be a cantilevered weight on the rear axle - I guesstimate 1000 lbs -- will I be exceeding Rear GAWR (Gross Axle Weight Rating, and I don't know what that is in lbs)? If not, I can try to address suspension geometry with air-bags.

As an option, I can mount a roof-top cargo carrier, and lighten the load on the rear hitch by 150 lbs. So hitch load would be 500 lbs = 800 lbs cantilevered.

What would be the penalty in MPG for a Roof-top Cargo Carrier?

There is no way the unibody structure as it stands can handle 700# weight like you plan, of course anything on the roof will reduce mileage, this whole idea sounds dangerous to begin with.

There is no way the unibody structure as it stands can handle 700# weight like you plan, of course anything on the roof will reduce mileage, this whole idea sounds dangerous to begin with.

Great to hear from you. Would 500 lbs be more manageable? What would the MPG penalty be (approx, or range) for the roof carrier?

I've hung 300# of motorcycle with 100# of hitch carrier on the back of my '00 with auto leveling suspension and it actually drove okay.

It did blow the shocks after I hit some big rolling bumps though.

I will say anything more than that is too much!

I think you are pushing the envelope here max tongue weight is about 250. The mileage with the roof load is hard to calculate, low speeds maybe not to bad, at 65 up, bad.

I think you are pushing the envelope here max tongue weight is about 250. The mileage with the roof load is hard to calculate, low speeds maybe not to bad, at 65 up, bad.

Not disagreeing, but I did it.

I used a class III hitch

That's not good on the load/weight.

About the MPG penalty for Roof Carrier -- I searched and found nothing. I would like to get a feel on it. I estimate 2-4 mpg less at 65-70 mph. But again, I don't have much experience with GM minivans and I am shooting from the hip. Maybe you guys that know these minivans a lot better, might provide a more educated guess?

You will take a good hit on the roof carrier, I would suspect 4mpg or so depending upon the shape/ material of the carrier.

OTOH, have you considered getting one of the extended length vans and putting some of your cargo in the rear behind the seats? Love mine.....

You will take a good hit on the roof carrier, I would suspect 4mpg or so depending upon the shape/ material of the carrier.

OTOH, have you considered getting one of the extended length vans and putting some of your cargo in the rear behind the seats? Love mine.....

I've had 2 Ford full-size vans (non-extended). Extended Econoline or Express is 2-3 feet longer than Venture, plus I would still need to hang the bikes off the back -- not good in the city. I am trying to not go there.

I think I can put 2 cargo boxes on the roof. Did that on my Volvo wagon (https://picasaweb.google.com/lh/photo/orHKWhdmhkUoYglqpeQHr-NU1DnohA0Uv5XV_7nC4U4?feat=directlink).


And a 3rd box (200 lbs) + 4 bikes on top of this box = 350-400 lbs on the hitch.

Keep in mind the hitch is not mounted to a "frame", it is bolted to some thicker parts of the unibody ribbing (the "frame" of the van")..... Good luck, let us know how it goes....