Can I use oil as a substitute for butter?!

Can I use oil as a substitute for butter?

I would like to make banana cake, but all the recipes I find call for butter. I just HATE butter and I can feel its taste even after baking.
Can I use oil instead of butter or what else can I use a substitute and how much?

You can try these :
If you need 1 cup butter , in baking cakes and quick breads You can substitute it with 1/2 cup applesauce plus 1/2 cup vegetable oil
OR
3/4 cup yogurt plus 1/4 cup vegetable oil


Butter Substitute

Any of a variety of alternate ingredients that can be used instead of oil or butter in the preparation of foods. Substitute products exist with reduced fat and no fat and in different forms such as spreadable and liquid oils. Examples of Butter Substitutes include Fruit oils, nut oils, vegetable oils, and oils from grains.
Fruit oils such as olive oil can be used as a substitute for butter in many instances. Instead of spreading butter on breads, olive oils can be served as dipping oils to add flavors to the bread. Olive oil is considered to be a healthy substitute because it contains a high concentration of monounsaturated fat identified by medical researchers as a fat which helps to reduce levels of LDL, or bad cholesterol in the human body. Fruit purees are readily avialable as a butter and oil subsitute for baking. A common product readily available in stores is a fruit-based puree made from dried plums and apples with additives which serves as a baking ingredient to replace butter in baked goods

Hope it helps