butter, but it will make whatever you're cooking have a thicker/richer taste, which is good in some cases, bad in others, depending on what it is you're making. it doesnt have to be REAL butter, it can be the butters that aren't really butters "i can't believe its not butter" or "country crock" or whatever else.
Yes, you can use canola oil instead of vegetable oil when making brownies.
You can use alternatives like avocado oil, coconut oil, or canola oil instead of olive oil for cooking or dressing.
no
no
yes
Yes, you can use 75w-90 gear oil instead of SAE 90 gear oil
Instead of using oil you can use butter this works just as well as oil sometimes even better .One bad thing is butter can be worse for your health then oil .Also there are oil sustitutes made out there.
Yes
Yes, you can. :)
If for baking, you can use sunflower oil.
Yes, you can use oil instead of butter when making cookies. However, the texture and flavor of the cookies may be slightly different when using oil.
Cork grease. :)