I would think olive oil would add a funky taste to granola, but that's just me. Canola oil would be a better choice, IMO.
I do love making the stuff at home, though, so I can control the amount of sugar.
The biggest thing for me with granola is moderation; since it's high calorie and I love it so much
. I've got white-chocolate cranberry granola bars calling my name this week from the kitchen counter and it's a struggle every time I make any kind of granola treat at home.