I used the semi synthetic version of the Q 4x4 a few years ago, and it worked great. Its just a slightly stronger add pack compared to the usual mix as far as I know.
It'll be fine for use in the cars as well.
The Q Horsepower/Torquepower/4x4 SUV, etc., etc. are all marketing ploys. I highly doubt there is any major difference between them except different additives and their ratios.
It'll be fine to run in your Sonata. I scored a bunch of Q Torquepower quarts for $2-2.50 that will be run in my Kia and Honda.
The base oil did have some differences on the old sheets, i.e. the "Horsepower" syn generally had a lower pour point (on par with Penn. Platinum) than did the Torquepower...
True: The pour point on the QHP is about 10 degrees lower than the QTP. But the TP is still at -23F which is no problem for me beacuse it rarely gets below -10F here. Then again, now that I have many jugs of TP it we will probably set -35F records next Winter...