this harbor freight model is basically the same one sold at autozone. the one you purchased there also has a lifetime warranty and autozone should have automatically registered that wrench at purchase. find your receipt.
napa and some wallyworlds carry this model/warranty. lots easier to return to one of these chain vendors than harbor freight...imo. i'm sure somebody will disagree with this observation.....
and why not buy the socket and extension on the same receipt? i wrapped my reciept around the wrench shaft and covered it with duck tape....so instead of it failing...i'll lose it!
they are all +-4%...in this price range....which is fine. infact some of the more expensive wrenches are less accurate.... 3-4 inch extension is plenty long IF you also get the long 3/4 inch socket.
as for torque values....this thread has got the real goods....
and a table in post 81 for all common a/s wheels/lugs/torque.
i agree get a socket for the t.v. too.
my ford is 165ft/lbs and the wrench only goes to 150...
but with the + side margin of error....