I would say that is about it with my little datsun truck as well as per a full load, quarter cord and some sticks..although I get closer to 40 MPG with the diesel engine in it. I have only hauled wood in it twice though, but I heaped it up regular like. Have done other heavier type loads. I do have additional half springs in the back, but it is an 81 after all and it was abused pretty hard before I got it, I know two of the previous owners and they ran the heck out of it hard.
I know the 4wd versions are much stouter, but they didnt release the diesel engine 4wds in the US, at least not too many (I think all canadian drive overs basically, what are here, which aint too many...). You can see on the yota thread though some pretty dang good loads.