Hanna wrote:
So if I have researched this correctly this is what I got.
04 Durango hemi limited with 3.55 gears
GCWR = 12,500
GVWR = 6,600 (5079 for truck and fluids and all options)(1520 for people and cargo)
So 12,500 - 6,600 = 5,900 for trailer and stuff packed in the trailer.
Apex trailer has base weight of 4,842 dry no gas or water. GVWR is 7,000 lbs.
7,000 - 5,900 left for towing = 1,100 over my GCWR.
04 Durango hemi limited with 3.92 gears
GVWR = 14,000
7,000 - 7,400 left for towing = 400 less then the 14,000 GCWR.
So if I swap out to the 3.92 gears I should be fine except for maybe length. Durango only has 40 k miles on it would hate to have to trade it in.
Please let know if I didn't under stand what I'm talking about please.
You need to make sure you understand what these numbers are telling you. You're not using them correctly. GVWR and GCWR are two separate things, and neither address a couple other important considerations.
Let's first look at GCWR since it's the easiest one to satisfy. GCWR is Gross Combined Weight Rating. It's the maximum amount of weight the vehicle should be expected to
pull. Assuming the trailer weighs 7000 and the SUV weighs 6600, that's GCW=13600 against a GCWR=12500. So with your SUV as-is, you're well over GCWR. If you do a gear swap, your GCWR=14000, and you're under by only 400. No matter how you look at it, you're really pushing this limit.
Another consideration is frontal area. Pulling a travel trailer with a high profile is
very different than pulling a cargo trailer. GCWR addresses only weight, but cruising down the highway, aerodynamic drag has a
far greater impact than weight on your ability to pull it. Even with a gear swap, that 400# headroom in GCWR is not enough to compensate IMO.
Now let's look at GVWR, which is Gross Vehicle Weight Rating. This is the maximum amount of weight the vehicle should be expected to
carry, and it's almost always the deal-killer for smaller tow vehicles. Yours is only 6600. You quoted 5079 dry weight, but have you taken it to the scales? I doubt it weighs in that light. But even if it does, you've got 1500# left. But you forgot to add in the tongue weight of trailer which is being carried by the SUV's chassis. A properly loaded trailer will have 12-15% of it's weight on the tongue to avoid sway. So when loaded, that trailer will have a tongue weight of close to 1000 pounds! Subtract that from the 1500#, and you've got only 500 left. And don't forget the weight of the hitch itself. 100-150# is about right. What about fuel? Does that weight include a full tank of gas? Probably not. Add another 150# for that. Now you've got only 250-300# left for people and cargo, which just isn't reasonable. Payload goes fast, and this is why GVWR is the biggest limiting factor for SUVs and 1/2 ton trucks.
Another consideration is wheelbase. A longer wheelbase provides more stability against sway. Longer trailers require trucks with longer wheelbases, plain and simple. Now I'm not one to say you have to limit yourself to 23', but I wouldn't even consider pulling a 31' trailer with only a 119" wheelbase.
As I see it, your SUV isn't just pushing the limit, it's over the limit in every category.
-- Rob
