mechjames,
You're going to have a great time on that road trip! I did the same thing with my girlfriend two years ago. She went to work in alberta for the summer and wanted her car to drive around.
I just changed the oil on her car with some dino before we left, and she had it changed before she returned. Like other's said, any synthetic would be ideal. I'd personally go with SSO, but I am a bit of an amsoil fanboy...in reality, anything of quality will do the job.
don't forget your tire pressure and other fluids!
I also highly recommend getting a CAA membership before you leave. I think mine is $90 a year and it could be a life saver for you if you blow a tire, or leave your lights on etc. You should also order a "trip tick" from them (they are free with your membership). They will plan out your full route for you on detailed maps that are around 100km scale each page. it lists construction areas, rest stops, places to stay etc. They were absoloutley AWESOME on this trip. They've got little history facts about the areas you pass through, too.
GPS is also a good investment it was nice to just drive into Saskatoon for lunch and explore, without worrying about getting lost.
The size of lake superior is ridiculous. that really hits home when it takes nearly 10 hours to drive it's length. it took me 22 hours of driving just to get out of ontario!
the point is, in what I'll call "northern" ontario you can drive many hours without seeing much civilization, the vast amounts of trees and wildlife we have it just amazing. For these reasons, make sure you fill up with gas frequently north of Sault ste. Marie. I think the biggest stretch was 300km between gas stations!