I want to drive 14 cubic feet of dirt 200 miles in the back of my Xtreme. It will weigh somewhere north of 1,000 lbs depending on how wet it will be. Now I see on the specs it has a "Payload" of 838 lbs, which seems kind of light to me, like only four people. I hope I'm reading that wrong or it has a 100% safety factor...

 

If the payload is 840 it is what it is as they say. Sounds like you're looking to exceed that by 20% or more. 200 miles is a pretty long way to go overloaded. Must be fancy dirt, can't get a trailer?

 

So when you drive these four people, each with 50 lbs of luggage, and a tankful of gas, what happens, exactly?

 

If it's more than 840 lbs you exceed the payload. Emergency handling, braking and wear/tear on components is all compromised. So technically, it's not safe and a lot can happen in 200 miles. Only you can say what you'd have to deal on this trip and if you want to do that. I've overloaded on short distances carrying wood and stuff but riding the axles long distance, nah.

A little overloaded is one thing but if between the dirt, that you said could be 1000 lbs or more, you and the gas you could easily reach 1400 lbs(?). I probably wouldn't do that. Trucks not built for it and it's not fair to other drivers.

 

The Blazer Xtreme has a lower weight capacity than the other models of Blazer due to the lower stance and different suspension. I'm pretty sure that the 840lbs is correct, and that does include passengers and any cargo/gear in the vehicle. Most other models of Blazer and Jimmy had a capacity of 1200-1300lbs.

That being said, you could try reducing the starting weight of your vehicle by removing things like the jack, spare tire, etc. to offset the extra weight of your cargo. That could save you close to 100lbs, but you'd only want to do this if you have a backup plan in case of a flat tire such as AAA or something.

As was suggested, a trailer might be a much better option if your Blazer is equipped to pull one.