Yes, by most accounts, they are excellent oils, especially for the money. Very good UOA's, as cheap or cheaper than most dinos and as good or better than them, too. For the money and reasonable oil change intervals (5K?), hard to beat.
They are both Conoco-Phillips blends, but I don't think they're *identical*. I think the add packs may be somewhat different, but I'm not sure about that. Note also the TropArtic is almost impossible to find in 5W-20, whereas the MC is sometimes/usually/frequently available in 5W-20 in the 5-qt jugs at Wal-Mart. And in qt bottles there and many other places. For 5w30, I'd buy the TropArtic for an inexpensive alternative to MC.
Yes, either would be fine in your Toyota. Use with confidence...they meet all the latest SM/GF4 specs and will meet or surpass Toyota's requirements. Just stick with the appropriate viscosity level and keep it to the recommended oci and you'll be fine. If you really, really want to know how either works, the best way is to do a UOA (used oil analysis).
As hominid said, both of these oils have been discussed at great length. Do the search and some reading and you'll get a lot more information than this brief post.
