Originally Posted by dc2123
I was curious what the purposes and uses were for different oils and which ones to avoid.
For me (and this won't be everyone's choice):
EVOO, walnut oil, cold pressed rape seed oil - mainly for salad dressings although I use EVOO when sautéing things quickly (It's no good for deep frying, regardless of what you might read in old cookery books, because it has a low smoke point.)
Sunflower oil and ordinary rapeseed oil* for deep-frying although I don't fry much. (Useful for adding to butter when frying as it prevents the butter from burning but doesn't affect the taste.)
Mustard oil for fish curries although I believe it is not cleared for food use in the USA
Personally, I don't like corn oil because it seems to me to leave a "clarty" feeling on your tongue and the roof of your mouth after you've eaten stuff cooked in it and IMO it's equally nasty in salad dressings.
We don't use much oil in baking in the UK as most recipes specify butter or margarine but when a recipe does crop up I would probably use sunflower oil as it's fairly light flavoured. Personally I think EVOO is a bit "in your face" flavourwise in cakes.
*I think but I'm not sure that rape seed oil is called canola in North America*