I'm sure I exceeded it on my trip to Nebraska last year. We had four adults, a baby plus baby seat, a completely full cargo area (with 'false floor' removed, it was still full-to-the-window,) and even some 'cargo' in the passenger compartment at people's feet. I know that the four adults alone hit the 800 pound mark. The 1500 miles to Nebraska, nothing bad happened. While IN Nebraska, we blew a tire, but that was on a nasty gravel road, and the tire truly disintegrated. (Little bits of black rubber gravel mixed in with the red rock gravel.) I blame that on the road, not on the load. (Punny rhyme really not intentional.) And the 1500 miles back were uneventful as well.
Both the trip there, and back, passed through really nasty winter weather in Wyoming, and it was a little squirrelly on the icy roads, but we had the stock tires then, too.